Stone retrieval balloon catheter

ABSTRACT

A device for removing a urinary tract stone from a ureter may include an outer shaft, an inner shaft extending coaxially within the outer shaft, a self-expanding wire basket attached to a basket shaft extending coaxially within the inner shaft, an inflatable balloon and a handle. The balloon main include a rounded distal tip. The handle may include an inversion slider coupled to the inner shaft and configured to actuate the inner shaft, thereby inverting the distal tip of the inflatable balloon to form a pocket adapted to receive a urinary tract stone. The handle may also include a basket slider coupled to the basket shaft and configured to actuate the basket shaft to move the wire basket in and out of the inner shaft.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/495,434, filed Apr. 24, 2017, now U.S. Pat. No. 9,743,944, entitled,“STONE RETRIEVAL BALLOON CATHETER.” The disclosure of this priorityapplication is hereby incorporated by reference in its entirety into thepresent application.

TECHNICAL FIELD

The present disclosure relates to medical devices and methods. Morespecifically, the disclosure relates to devices and methods for removingurinary tract stones.

BACKGROUND

Kidney stones (also known as urinary tract stones, ureteral stones orureteral calculi in medical terminology) are a significant burden onsociety and health care systems. Kidney stones form in the body when theamount of various minerals in urine exceeds an amount that can beeliminated (the metastable limit), and the excess minerals form aprecipitate. Most kidney stones are comprised of calcium and oxalate,though uric acid, struvite, cysteine, and other stone compositions arealso common.

Kidney stones typically form in the parts of the kidney known as therenal pelvis or calyces and can stay there for years. When a stonedislodges, it makes its way down the upper urinary tract towards thebladder. Stones often get stuck en route to the bladder in the ureter.One reason for this is that mechanical rubbing of the sharp stone on theureter's mucosal lining causes an inflammatory response and swelling (or“edema”), which inhibits the stone's ability to pass. This obstructionimpedes the passage of urine from the kidney to the bladder, whichresults in increased internal pressure in the kidney. This pressure risecauses nerve fibers in the kidney to stretch, which in turn results inthe excruciating pain well known to accompany stones. Clinically, thispain is known as “renal colic” and comes in unexpected bursts lasting2-18 hours, until the internal pressure of the kidney is reduced. Aslong as the stone remains in the urinary tract, a patient will be atrisk for renal colic. Female patients describe stones as worse thannatural childbirth, while male patients describe it as the mostexcruciating experience of their lives.

Pain relief from kidney stones typically occurs instantly after stonepassage or removal. Waiting for kidney stones to pass, however, can be along and painful process. Currently, three general types of kidney stoneremoval methods are used, all of which have at least some shortcomings.

Extracorporeal Shockwave Lithotripsy (ESWL) is a procedure in whichshockwaves are transmitted through the body in the direction of a kidneystone, in an attempt to fragment the stone into smaller pieces. For theESWL procedure, a patient lies on a special bed (which costsapproximately $750,000), is given sedation anesthesia, and is bombardedwith 45-90 shocks per minute over the course of 45 minutes to one hour.The shocks are so intense that they must be synchronized with thepatient's heartbeat so as not to cause cardiac arrhythmias. ESWLoutcomes are mixed: 33% of patients have a successful outcome and pass“sand,” 33% of patients pass several smaller stones with excruciatingpain, and 33% of patients are unaffected by the treatment. Recentstudies have raised concerns about potential long-term complications ofESWL, including hypertension and diabetes. Due to the uncertainoutcomes, required sedation anesthesia, and potentially hazardousmechanism of the treatment, ESWL is indicated only for patients with8-13 mm stones located in the kidney itself. Generally, stones of thissize and location are asymptomatic.

Ureteroscopy (URS) is a procedure in which a urologist inserts anendoscope up the urethra, into the bladder, and up the ureter to thesite of the stone. Using a laser, the urologist fragments the stone intosmaller pieces and retracts the fragments with a retention member. Theprocedure requires general anesthesia, high skill level from theurologist, and anywhere from 20 minutes to one hour. The endoscope,laser source, and fluoroscopy require an investment of approximately$225,000 in capital equipment alone. The ureteroscopes themselves costapproximately $15,000 and can typically be used in only about 15procedures before needing to be replaced or repaired. The typical amountof manipulation of the ureteroscope within the ureter during theprocedure, as well as the overall time spent in the ureter, can induceureteral stricture (blockages of the ureter caused by a process similarto scarring). The procedure outcome is generally highly effective, butdue to the risk of complications and required general anesthesia, URS isgenerally recommended only for stones that are 8-15 mm in size.

Percutaneous Nephrectomy Lithotripsy (PCNL) is a surgical procedure inwhich a tube is inserted through the back into the kidney. Stones areremoved through the tube, using lasers, graspers, and aspiration. ThoughPCNL is highly effective, its invasiveness renders it applicable only tostones larger than 15 mm.

As described above, the currently available procedures for kidney stoneremoval are generally quite invasive and require (1) at least sedationanesthesia and in many cases general anesthesia, (2) expansive,specialized capital equipment, and (3) experienced and knowledgeableurologists to perform the procedures. Furthermore, most small kidneystones ultimately pass without any intervention. Therefore, despite theincredible, debilitating pain involved in passing kidney stonesnaturally, that is typically the method of choice, since kidney stoneremoval methods have such significant drawbacks.

Thus, it would be advantageous to have additional treatment options forkidney stone removal. Ideally, these options would be less invasive,less expensive, less prone to side effects, and/or require lessphysician expertise to perform. It would also be ideal if some of theadditional treatment options could be used, or adapted for use, in otherparts of the body to remove other obstructions. At least some of theseobjectives will be met by the embodiments described herein.

SUMMARY

This disclosure describes a device and method for treating urinary tractstones. In various embodiments, the device and method may be used toremove whole urinary tract stones and/or kidney stone fragments (such asthose produced via a lithotripsy procedure) using a flexible catheterstone removal device advanced through a ureteroscope. In someembodiments, the stones and/or fragments retrieved and removed by thedevice and method may have diameters of less than about 5 mm, althoughsome embodiments may be designed to address larger stones and fragments.In general, in this disclosure, the terms “kidney stone,” “urinary tractstone,” “urinary tract stone” and “stone” may be usedinterchangeably/synonymously and should be interpreted to include stonefragments as well as whole stones.

In some embodiments, the device and method described herein may also beused for gently dilating the ureteral tract. Dilation may be used toopen up a narrow section of the ureter and/or provide temporaryexpansion, if force being used to remove a stone from the ureter becomeshigher than acceptable for the user. Additionally, the device and methoddescribed herein may also be used to prevent retropulsion of kidneystone fragments back into the kidney during a stone fragmentationprocedure (e.g., lithotripsy).

In one aspect of the present disclosure, a device for removing a urinarytract stone from a ureter may include: an outer shaft; an inner shaftextending coaxially within the outer shaft; a self-expanding wire basketattached to a basket shaft extending coaxially within the inner shaft;an inflatable balloon; and a handle. The wire basket expands from acollapsed configuration inside the inner shaft to an expandedconfiguration when advanced out of a distal end of the inner shaft. Theballoon includes distal attachment leg attached to the inner shaft, arounded distal tip immediately proximal to the distal attachment leg, atapered proximal portion, and a proximal attachment leg attached to theouter shaft immediately proximal to the tapered proximal portion. Thehandle is coupled with proximal ends of the outer shaft, the innershaft, and the basket shaft, and it includes an inversion slider coupledto the inner shaft and configured to actuate the inner shaft, therebyinverting the distal tip of the inflatable balloon to form a pocketadapted to receive a urinary tract stone, and a basket slider coupled tothe basket shaft and configured to actuate the basket shaft to move thewire basket in and out of the inner shaft. The basket slider is coupledvia a friction coupling with the inversion slider, such that when theinversion slider is moved along the handle to invert the distal tip ofthe inflatable balloon, the basket slider automatically moves along withthe inversion slider to move the wire basket into the distal tip of theinflatable balloon.

In some embodiments, the inflatable balloon has a tubular middle portionbetween the rounded distal tip and the tapered proximal portion, and alongitudinal length of the tapered proximal portion is two times toeight times longer than a length of the rounded distal tip. In someembodiments, the inflatable balloon has a first thickness at the taperedproximal portion and a second thickness at the rounded distal tip, andthe first thickness is greater than the second thickness. In someembodiments, the basket slider is independently moveable, relative tothe inversion slider. Some embodiments may also include an inversionslider lock within the handle, for locking the inversion slider to thehandle to prevent its movement when the basket slider is being moved. Insome embodiments, pushing down on the inversion slider unlocks theinversion slider from the inversion slider lock. In some embodiments,the friction coupling is configured to be overridden by a user, ifdesired, by placing a finger on the basket slider to prevent itsautomatic movement with the inversion slider. In some embodiments, theinversion slider is located on a side surface of the handle, and thebasket slider is located on a top surface of the handle.

In some embodiments, a space between the outer shaft and the inner shaftcomprises an inflation lumen for the inflatable balloon, and the handlefurther includes a balloon infusion port in fluid communication with theinflation lumen. Some embodiments of the device may optionally include afirst hypotube attached to a proximal portion of the outer shaft and asecond hypotube attached to a proximal portion of the inner shaft, wherethe second hypotube is configured to telescope within the firsthypotube. In some embodiments, the outer shaft may have an outerdiameter of less than 1.2 mm. In some embodiments, the inflatableballoon may have a diameter, when inflated, of at least 5 mm.Optionally, the inflatable balloon may include multiple, longitudinalpleats.

In another aspect of the present disclosure, a method for removing aurinary tract stone from a ureter may involve: advancing a distal end ofa ureteroscope into the ureter to a location near the urinary tractstone; advancing a distal end of a flexible stone removal device out ofthe distal end of the ureteroscope; sliding a basket slider distallyalong a handle of the stone removal device to advance a wire basket outof an inner shaft of the stone removal device, thus allowing the wirebasket to expand; sliding the basket slider proximally along the handleto trap the urinary tract stone within the wire basket; inflating aninflatable balloon on the stone removal device; and sliding an inversionslider proximally along the handle to invert a rounded distal tip of theinflatable balloon. The inversion slider may be frictionally coupledwith the basket slider, and sliding the inversion slider proximally mayautomatically slide the basket slider proximally to pull the wire basketand the trapped urinary tract stone into the rounded distal tip of theinflatable balloon. Finally, the method involves removing theureteroscope and the stone removal device from the ureter, along withthe urinary tract stone, while the urinary tract stone is at leastpartially located inside the inflatable balloon.

Optionally, the method may also involve unlocking the inversion sliderbefore sliding it proximally along the handle. The method may alsoinvolve visualizing at least one of the steps of the method, using theureteroscope. Advancing the distal end of the stone removal device mayinvolve advancing the distal end of the device distally beyond theurinary tract stone, and the method may further involve pulling thestone removal device proximally to surround the urinary tract stone withthe wire basket. In various embodiments, the urinary tract stone may beeither a complete stone or a urinary tract stone fragment. For example,in some embodiments, at least part of the method is performed during alithotripsy procedure, to help prevent movement of a urinary tract stonefragment into the kidney.

In some embodiments, the method may further involve depressing theinversion slider before sliding it, to unlock the inversion slider froman inversion slider lock in the handle. Some embodiments may furtherinvolve holding a finger on the basket slider during movement of theinversion slider to override the automatic movement of the basketslider. In some embodiments, sliding the basket slider does notautomatically move the eversion slider when the eversion slider islocked in an inversion slider lock in the handle. In some embodiments,the inflatable balloon is inflated sufficiently to dilate a narrowportion of the ureter. The method may optionally also involve inflatingthe balloon at least one time during removal of the stone removal devicefrom the ureter, to dilate a narrow portion of the ureter. The methodmay also optionally involve removing air from the inflatable balloon toreduce pressure in the inflatable balloon before inverting the roundeddistal tip of the inflatable balloon. In some embodiments, the urinarytract stone being removed will be less than 5 mm in diameter.

In another aspect of the disclosure, a method for facilitating removinga urinary tract stone from a ureter may involve: advancing a distal endof a ureteroscope into the ureter to a location near the urinary tractstone; visualizing the ureter, using the ureteroscope; advancing adistal end of a flexible stone removal device out of the distal end ofthe ureteroscope; inflating an inflatable balloon on the stone removaldevice to expand a portion of the ureter and thus facilitate passage ofthe urinary tract stone through the expanded portion of the ureter; andvisualizing the urinary tract stone, using the ureteroscope.

In some embodiments, the method may further include: sliding a basketslider distally along a handle of the stone removal device to advance awire basket out of an inner shaft of the stone removal device, thusallowing the wire basket to expand; sliding the basket slider proximallyalong the handle to trap the urinary tract stone within the wire basket;and sliding an inversion slider proximally along the handle to invert arounded distal tip of the inflatable balloon; and removing theureteroscope and the stone removal device from the ureter, along withthe urinary tract stone, while the urinary tract stone is at leastpartially located inside the inflatable balloon. The inversion slidermay frictionally coupled with the basket slider, and sliding theinversion slider proximally may automatically slide the basket sliderproximally to pull the wire basket and the trapped urinary tract stoneinto the rounded distal tip of the inflatable balloon. Some embodimentsmay involve unlocking the inversion slider before sliding it proximallyalong the handle. Some embodiments may involve reducing pressure in theinflatable balloon before inverting the rounded distal tip of theinflatable balloon.

These and other aspects and embodiments are described in further detailbelow, in relation to the attached drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are perspective and side views, respectively, of asystem for removing kidney stones from ureters or other obstructionsfrom other body lumens, according to one embodiment;

FIGS. 2A and 2B are perspective views of a distal portion of the systemof FIGS. 1A and 1B, illustrating a portion of a method for retaining akidney stone in the system, according to one embodiment;

FIGS. 3A and 3B are side cross-section and end-on cross-section views,respectively, of a kidney stone removal system similar to the system ofFIGS. 1A, 1B, 2A and 2B;

FIGS. 4A-4E are schematic side views of a ureter and kidney stone,illustrating a method for removing a stone from a ureter using a systemsuch as that described in FIGS. 1A, 1B, 2A, 2B, 3A and 3B, according toone embodiment;

FIGS. 5A-5F are schematic side views of a ureter and kidney stone,illustrating a method for removing a stone from a ureter using a systemsuch as that described in FIGS. 1A, 1B, 2A, 2B, 3A and 3B, according toan alternative embodiment;

FIGS. 6A and 6B are perspective views of a distal portion of a kidneystone removal system having an expandable basket and a funnel member,according to an alternative embodiment;

FIGS. 7A and 7B are perspective and close-up views, respectively, of anexpandable grasper that may be a part of a kidney stone removal system,according to an alternative embodiment;

FIGS. 8A and 8B are perspective views of a distal portion of a kidneystone removal system (FIG. 7B shown within a ureter with a kidney stone)having an expandable grasper and a compliant membrane, according to analternative embodiment;

FIG. 9 is a side view of a distal portion of a kidney stone removalsystem having an expandable grasper and an inflatable balloon, accordingto an alternative embodiment;

FIG. 10 is a perspective view of a distal portion of a kidney stoneremoval system having an expandable grasper, a compliant membrane and acamera, according to an alternative embodiment;

FIGS. 11A and 11B are side views of a distal portion of a kidney stoneremoval system having an expandable mesh basket and an inflatableballoon, according to an alternative embodiment;

FIG. 12 is a perspective view of a distal portion of a kidney stoneremoval system having an expandable mesh basket and a webbing betweenthe mesh, according to an alternative embodiment;

FIGS. 13A and 13B are perspective and side views, respectively, of adistal portion of a kidney stone removal system having a balloon,according to one embodiment;

FIG. 14A is a perspective view of a distal portion of a kidney stoneremoval system having a balloon, according to an alternative embodiment;

FIG. 14B is a perspective view of a distal portion of a kidney stoneremoval system having a balloon, according to another alternativeembodiment;

FIGS. 15A and 15B are side cross-sectional and end-on cross-sectionalviews, respectively, of a distal end of a kidney stone removal device,according to another embodiment;

FIGS. 16A and 16B are side cross-sectional and end-on cross-sectionalviews, respectively, of a distal end of a kidney stone removal device,according to another embodiment;

FIG. 17 is a perspective view of a kidney stone removal device,according to one embodiment;

FIGS. 18A-18D are side views of the kidney stone removal device of FIG.17, illustrating an example procedure of capturing a kidney stone withthe device, according to one embodiment;

FIGS. 19A-19E are side views of a kidney stone removal device accordingto an alternative embodiment, illustrating an alternative procedure forcapturing a kidney stone with the device;

FIG. 20A is a perspective view of a kidney stone removal device,according to another alternative embodiment;

FIG. 20B is a partial cross-sectional view of a distal portion of thekidney stone removal device of FIG. 20A;

FIGS. 20C-20E are partial cross-sectional views of the distal portion ofthe kidney stone removal device, as in FIG. 20B (in the left-hand panelsof the figures) and side views of the corresponding distal portion ofthe kidney stone removal device (in the right-hand panels of thefigures), illustrating movement of sliders on the handle of the deviceand corresponding movements of the distal portion of the device,according to one embodiment;

FIG. 20F is a side view of a distal portion of the kidney stone removaldevice of FIGS. 20A-20E;

FIGS. 21A-21F are perspective views of a ureteroscope and a distal endof the kidney stone removal device of FIGS. 20A-20F, illustrating amethod for removing a kidney stone from a ureter, according to oneembodiment; and

FIGS. 22A and 22B are front views of two embodiments of a balloon of akidney stone removal device, illustrating optional pleats in theballoon, according to some embodiments.

DETAILED DESCRIPTION

This application describes a number of embodiments of devices, systemsand methods for removing obstructions from body lumens and passageways.Although the embodiments are described primarily for use in removingkidney stones from the urinary tract, at least some of the embodimentsmay also be used, or may be adapted for use, in other parts of the bodyto remove other obstructions. Therefore, the following descriptionshould not be interpreted as limiting the scope of this application tokidney stone removal, since any embodiment described may be used oradapted for other uses. The terms “kidney stone,” “stone” and“obstruction” may be used interchangeably herein. Additionally, althoughmany of the descriptions below focus on removal of a kidney stone fromthe ureter, other parts of the body and/or other obstructions may beaddressed in other embodiments. The terms “lumen” and “vessel,” forexample, may be used generally and interchangeably to refer to areas inwhich obstructions may be located.

Generally, this application describes devices, systems and methods forremoving kidney stones from ureters (or other obstructions from otherbody lumens). In some embodiments, kidney stone removal may be performedwithout fragmenting the stones before removal. Alternatively, someembodiments may be used to remove fragmented stones. The variousembodiments of devices, systems and methods described herein typicallyinclude one or more elongate, flexible shafts, arranged coaxiallyrelative to one another, one or more end effectors at the distal end ofthe shaft(s) for removing the kidney stone, and a handle at the proximalend of the shaft(s) for manipulating the shaft(s) and end effector(s).It may be advantageous to include, in each embodiment, at least two ofthe following three aspects. It may be most advantageous to include allthree aspects in a given embodiment, and some embodiments do include allthree, but that is not a requirement.

Obstruction retention. This refers to a mechanism for retaining orotherwise applying a force to the kidney stone or other obstruction forthe purpose of retaining, manipulating and eventually removing theobstruction. Several examples of obstruction retention members describedbelow include, but are not limited to, expandable graspers, expandablebaskets and expandable balloons with cavities for trapping obstructions.

Ureter wall protection. This refers to a mechanism for protecting theureteral wall (or wall of another lumen or vessel) from trauma caused bythe stone or other obstruction rubbing against the wall during removal.In some but not all embodiments, ureter/vessel wall protection mayinvolve ureteral/vessel dilation. Such embodiments may include amechanism to provide dilation around the obstruction to reduce frictionand eliminate trauma to the lumen wall caused by contact of theobstruction surface with the lumen wall. Generally, embodiments mayinvolve any soft, compliant or low-friction material that may bepositioned between the stone and the ureter wall. Several examples ofureter wall protection members described below include, but are notlimited to, expandable balloons, shafts, and hydrodilation members thatemit fluid to expand the ureter/vessel/lumen.

Obstruction detection and/or identification. This refers to a mechanismto identify the obstruction location and ensure retention and/ordilation is applied in the proper location relative to the obstruction.Detection may also be used to ensure removal of the stone and forgeneral navigational purposes in the lumen or other orifice. One exampleof an obstruction detection member described below includes, but is notlimited to, a fiber optic camera incorporated into an obstructionremoval device. As another example, fluoroscopy may be used to visualizeone or more aspects of a procedure, including device navigation.

Many of the embodiments of devices, systems and methods described belowmay include one mechanism from each of the three categoriesabove—obstruction retention, ureter wall protection and obstructiondetection. This combination may be advantageous in providing foreffective kidney stone removal with minimal trauma to the ureter. Inmany embodiments, it will be possible to combine different mechanismsfrom one category with different mechanisms from another category toform an alternative embodiment. For clarity, the descriptions below willnot always repeat details about various mechanisms from each categoryfor each embodiment. For example, if a fiber optic camera is describedin relation to one embodiment as a stone detection mechanism, that samecamera need not be described again in detail for use with anotherembodiment. Mechanisms from each of the three categories may be combinedwith each other in any suitable way to form various alternativeembodiments.

Referring to FIGS. 1A-1B, in one embodiment, a kidney stone removalsystem 10 may include a handle 12, a handle extension 14, an outer shaft16 and an end effector 18. In one embodiment, end effector 18 mayinclude an expandable stone retention member 20 (also referred to inthis embodiment as “basket 20”), a visualization device 22 (alsoreferred to in this embodiment as “camera 22”), and a wall protectionmember 24 (also referred to in this embodiment as “inflatable balloon24”). Handle extension 14, as mentioned above, is simply a slidingportion of handle 12, which slides out of and back into the distal endof handle 12. It is an optional feature. In this embodiment, handleextension 14 is coupled with a balloon fill port 26, an irrigation port28 and a shaft slider 30. Handle 12 may include a retention memberslider 32 and may be coupled with a camera proximal portion 34, whichmay include an imaging sensor (and electronics) and/or a light source insome embodiments. Many of these features are described in further detailbelow.

In various embodiments, end effector 18 may include a number ofvariations, such as different components, differently sized components,and the like. For ease of description, end effector 18 is referred tohere as a distal portion of system 10, which includes multiple differentkidney stone removal components. Alternatively, the term “end effector”may be used elsewhere herein to refer to one component at or near thedistal end of system 10. In the embodiment illustrated in FIGS. 1A and1B, end effector 18 includes stone retention member 20, which includes aretention member shaft (not visible in FIGS. 1A and 1B) and anexpandable, stone retention portion extending distally from a distal endof the retention member shaft. In this embodiment, the stone retentionportion is an expandable basket. Again, the terms “stone retentionmember 20” and “basket 20” may be used interchangeably herein, althoughthe stone retention member may comprise a one-piece or attachedretention member shaft and expandable stone retention portion. Inalternative embodiments, the stone retention portion of stone retentionmember 20 may be something other than an expandable basket, such as anexpandable cup, tongs or the like.

Basket 20 may be made of Nitinol, spring stainless steel, shape memorypolymer, or any other suitable shape-memory material. Basket 20 may bean extension of (or alternatively attached to) a distal end of theretention member shaft, which may be disposed within an inner shaft (notvisible in FIGS. 1A and 1B). The inner shaft, in turn, is located withinouter shaft 16. The various relationships of the shafts, according to atleast one embodiment, are described in further detail below, in relationto FIGS. 3A and 3B. Generally, basket 20 is housed within the innershaft during advancement of shaft 16 into and through the ureter. Basket20 is then advanced distally out of the inner shaft to be released fromconstraint. Upon release from constraint, basket 20 expands and may thenbe used to trap a kidney stone. Basket 20 may include any suitablenumber of struts, such as but not limited to the four struts illustratedin FIGS. 1A and 1B.

In some embodiments, end effector 18 may also include visualizationdevice 22 (or “camera 22”) for detection and visualization of kidneystones. Visualization device 22 refers generally to the entire deviceused in system 10 for visualization and not just the distal tip ofdevice 22 that is illustrated in FIGS. 1A and 1B. For example, camera 22typically extends from a distal end, located at or near a distal end ofthe inner shaft, through the inner shaft, to camera proximal portion 34,which is attached to handle 12. Camera 22 may be any suitable smallcamera, such as but not limited to a fiber optic camera, a CCD(charge-coupled device) image sensor or a CMOS (complementarymetal-oxide-semiconductor) camera. Camera proximal portion 34 may beattached via a cable with one or more conductors to an image-processingconsole (not shown), which displays an image on a viewing screen.Alternatively, camera proximal portion 34 may contain an eyepiece,through which an image may be observed and/or magnified using othertechniques common in the art of endoscopy. The distal, viewing end ofcamera 22 is located in end effector 18, so that it may be used tovisualize a kidney stone located in the ureter in front of system 10. Insome embodiments, camera 22 is located coaxially within the retentionmember shaft (again, not shown in FIGS. 1A and 1B but illustratedlater), with its distal end positioned at or near a distal end of theinner shaft and/or the retention member shaft. The retention membershaft extends distally to form basket 20, and the distal tip of camera22, in these embodiments, generally faces directly into the expandableportion of basket 20.

In some embodiments, the distal end of camera 22 may be fixed in place,relative to the distal tip of the inner shaft. Camera 22 extends fromits distal end, proximally through the retention member shaft to cameraproximal portion 34, which is coupled with handle 12. In variousembodiments of system 10, any suitable camera 22 currently available oras yet to be invented may be used. Furthermore, although visualizationdevice 22 is referred to herein as a “camera,” any other suitablevisualization device may be used in alternative embodiments. In someembodiments, system 10 may include camera 22, while in otherembodiments, system 10 may be provided without camera 22, and any of anumber of available cameras may be added to system 10.

Finally, end effector 18 may also include wall protection member 24,also referred to as inflatable balloon 24, which is used both forprotecting the ureteral wall from trauma and also to aid in stoneretention. In alternative embodiments, some of which are describedbelow, wall protection member 24 may be something other than aninflatable balloon, such as a compliant cup or other form of compliantmaterial. Thus, use of the term “balloon” in describing the presentembodiment should not be interpreted as limiting. Balloon 24 may also beused to help maintain a position of system 10 relative to the ureter,once it is inflated. Additionally, balloon 24 may be used duringadvancement or withdrawal of system 10 into or out of the ureter, toexpand a portion of the ureter, for example to expand a constriction orother narrowing of the ureter. Balloon 24 may be made of any suitablepolymer, polymeric blend or other material or combination of materials.Generally, such material(s) will be relatively atraumatic to theureteral wall and ideally will have a low-friction and/or hydrophilicouter surface or coating that facilitates sliding along the wall. Insome embodiments, balloon 24 may be coated with a lubricious coatingand/or may include one or more small holes for allowing a lubricatingfluid to escape.

As will be described in further detail below, in one embodiment, endeffector 18 may be advanced through the ureter to a location near thekidney stone. The small, inner shaft, containing basket 20, may beextended out of outer shaft 16 during all, or at least part of, thisadvancement, and the whole device may be advanced until a distal end ofthe inner shaft is advanced beyond the stone. Basket 20 may then beadvanced out of the inner shaft to allow it to expand, and the wholedevice may be pulled back to capture the stone. Camera 22 is coaxiallylocated within the retention member shaft (or “basket shaft”) and ispositioned with its distal end at or near a distal end of the innershaft and/or the retention member shaft, so that it faces into basket 20to help visualize the stone and the process of capturing the stone. Oncethe stone is trapped in basket 20, inflatable balloon 24 may beinflated, typically until it contacts the inner wall of the ureter.Basket 20 and stone may then be pulled back proximally into the distalend of balloon 24, such that balloon 24 invaginates to receive andenvelop at least part of basket 20 and stone. At this point, system 10may be withdrawn from the ureter, with balloon 24 helping to preventtrauma to the ureteral wall and reducing the amount of force required toremove the stone. In some embodiments, irrigation fluid for enhancingvisualization and/or lubrication may also be introduced into the ureterduring the method. Although suction may also be used in some embodimentsto help trap and/or retain the stone in basket 20, it is not a necessarycomponent of the system or method. This is only one embodiment of amethod for stone removal, and this embodiment and alternativeembodiments are described in further detail below.

In one embodiment, handle extension 14 slides at least partially intoand out of handle 12 to advance and retract one or more of the shafts ofsystem 10. Handle extension 14 is an optional feature, and inalternative embodiments it may be eliminated. Additionally, themovements of the various shafts of system 10 described herein areexemplary in nature and should not be interpreted as limiting. Someshafts move relative to other shafts, and some shafts may be fixedrelative to handle 12 or handle extension 14. For example, in oneembodiment, camera 22 may be fixed to handle 12, so that it does notmove during use of system 10, and instead, other parts move around it.This relationship may be advantageous, because it may reduce wear andtear on camera 22, which in some embodiments may be reusable. The innershaft, which again will be shown and described in greater detail below,may also be fixed to handle 12 in one embodiment, so that the innershaft covers most or all of the long, thin, flexible portion of camera22 at all times. In alternative embodiments, however, the variousrelative movements and relationships described herein may be changed,without significantly changing the overall function of system 10.Therefore, the descriptions of shaft movements, actuators, movement ofhandle extension 14 and the like should not be interpreted as limitingthe scope of the invention as it is described in the claims.

In one embodiment, handle extension 14 is fixedly attached to outershaft 16, such that handle extension 14 and outer shaft move together,relative to handle 12 and the inner shaft that houses basket 20. Handleextension 14 may slide in and out of handle 12 by manipulating shaftslider 30, which is fixedly attached to extension 14. Handle extension14 may also include balloon fill port 26, which may be coupled with asource of balloon inflation fluid, such as but not limited to salinesolution, water or contrast agent.

Handle extension 14 may also include irrigation port 28, which may becoupled with a source of irrigation fluid, such as but not limited tosaline solution, water or a solution including a pharmaceutical agent,such as lidocaine. The irrigation fluid may exit system 10 near thedistal (viewing) end of camera 22, for example out of a space betweenthe distal end of the inner shaft and the distal end of the retentionmember shaft, or alternatively, through one or more irrigation fluidapertures on the inner shaft, the wall retention member or the like.Irrigation fluid may be used, for example, to help enhance visualizationby keeping the distal end of the camera 22 clean and/or expanding acollapsed ureteral lumen, thus increasing the ability to visualize thelumen itself. Additionally, irrigation fluid may help to reduce frictionwhile removing the kidney stone, to reduce pain, for example whenlidocaine is used as lubricant, and/or for any combination of these orother purposes. In some embodiments, irrigation fluid may be passed outof the distal end aperture(s) or channel(s) at a low flow rate—forexample, less than 5 cc/min. This low flow rate might be lower, forexample, than flow rates typically used with currently availableendoscopes for irrigation.

In one alternative embodiment, irrigation port 28 and balloon fill port26 may be combined into a common port fluid infusion port. For example,in one embodiment, inflation fluid may also act as irrigation fluid byexiting out of the inflated balloon through one or more small apertures.Alternatively, fluid may enter the combined port and may then bedirected into a balloon inflation lumen and an irrigation fluid lumen.

Handle 12 couples with camera proximal portion 34 and also may includeretention member slider 32, which is attached to the proximal end of theretention member shaft. Retention member slider 32 may be used toadvance and/or retract basket 20 out of and/or into the inner shaft.Handle 12 also provides a portion of system 10 that a user mayconveniently grasp with one hand. Slider(s) 30 and/or 32 may bemanipulated with the same hand that holds handle 12 or with the oppositehand. Handle 12 and handle extension 14 may be made of metal, polymer, acombination of metal and polymer, or any other suitable material orcombination of materials. Outer shaft 16 may be made of any suitable,biocompatible, flexible polymer. In some embodiments, system 10 may befully disposable. In alternative embodiments, camera 22 may be reusable,and the rest of system 10 may be disposable. Finally, it may be possiblethat in some embodiments all of system 10 may be reusable andsterilizable, such as by autoclave or other sterilization processes.

In some embodiments, the proximal end of outer shaft 16 may removablyattach to the distal end of handle extension 14, for example by asnap-on fit in one embodiment. This snap-on configuration may have twoprimary advantages. First, outer shaft 16 may be attached to handle 12after shaft 16 has been advanced into the ureter through an endoscope(such as but not limited to a cystoscope or steerable shaft) to positionthe distal end of shaft 16 in a desired location for stone removal. Thisallows the physician user to remove the endoscope after positioning theouter shaft 16 and prior to operation, improving patient comfort andease of use. Second, handle 12 may be reusable, even if some or all ofthe rest of system 10 is disposable.

Referring now to FIGS. 2A and 2B, a distal portion of system 10 isillustrated in greater detail. In these figures, a kidney stone S isshown trapped inside basket 20. In some embodiments, balloon 24 may haveseveral distinct portions, such as a proximal attachment portion 35attached to outer shaft 16, a proximal tapered portion 36, a middleportion 37, a distal tapered portion 38 and a distal attachment portion39 attached to a wall protection member shaft 42. Generally, it may beadvantageous for proximal tapered portion 36 to have a more gradualtaper than distal tapered portion 38. For example, in some embodiments,proximal tapered portion 36 may have a taper angle of between about 5degrees and about 25 degrees, and ideally between about 10 degrees andabout 15, relative to a longitudinal axis of balloon 24. Distal taperedportion 38 may have a taper angle of between about 30 degrees and about90 degrees, and ideally between about 40 degrees and about 70 degrees,relative to the longitudinal axis of balloon 24. In one specificexample, distal tapered portion 38 may have a taper angle of about 45degrees, and proximal tapered portion 36 may have a taper angle of about10 degrees. The “steeper” taper angle of distal tapered portion 38relative to that of proximal tapered portion 36 will cause distaltapered portion 38 to preferentially collapse into balloon 24 (or“invaginate”) when basket 20 and stone S are pulled back into distaltapered portion 38, rather than having any proximal tapered portion 36collapse. Additionally, the steeper taper angle of distal taperedportion 36 may facilitate engulfing the stone with balloon 24 with lessrelative movement between outer shaft 16 and the inner balloon shaft. Inone embodiment, described further below, distal tapered portion 36 maybe rounded rather than tapered.

FIG. 2B illustrates this preferential invagination of distal taperedportion 38. Although distal tapered portion 38 is not visible in FIG.2B, it has been pulled back into balloon 24 by basket 20 and stone S,which middle portion 37 and proximal tapered portion 36 remainrelatively in the same configuration. As basket 20 and stone S arepulled further into balloon 24, part of middle portion 24 may be made toinvaginate into the interior of balloon 24, and in this way all or partof stone S may be encircled by balloon 24. Basket 20 and stone S may bepulled proximately by sliding the retention member shaft (not visiblehere, because it is within wall protection member shaft 42 and the innershaft) proximally, for example via a slider on handle 12 or handleextension 14. Pulling basket 20 and stone S proximally into balloon 24may cause wall protection member shaft 42 to slide proximally as balloon24 invaginates. In some embodiments, distal attachment portion 39 andproximal attachment portion 35 may be of approximately equal lengths.Alternatively, they may have different lengths.

Balloon 24 may serve a number of different functions. For example,balloon 24 may reduce friction against the ureter wall by the trappedstone during removal, it may reduce trauma of the ureter wall by sharpedges of a trapped stone, and/or it may help retain the stone withinsystem 10 in general. The retaining function may occur if balloon 24surrounds the stone partially or completely and thus helps with thetrapping/retaining of the stone. In other words, balloon 24 and basket20 may work together to trap and retain the stone.

In some embodiments, as an alternative or in addition to havingdifferent taper angles, distal tapered portion 38 and proximal taperedportion 36 may also have different thicknesses, be made of differentmaterials, include one or more rigidity and/or flexibility features,and/or the like. In one embodiment, for example, proximal taperedportion 36 may be thicker than distal tapered portion 38, again topromote preferential collapse/invagination of distal tapered portion 38before any other portion of balloon 24. In one embodiment, for example,a thicker balloon wall of proximal tapered portion 36 may be achieved ina dipping manufacturing process by dipping proximal tapered portion 36more times than distal tapered portion 38. In another embodiment, whereballoon 24 is formed using a balloon blowing process, an additionallayer at proximal tapered portion 36 may be added after formation ofballoon 24. This layer may be a simple adhesive, additional balloonmaterial, or some other material that will bond to the blown balloonsurface. Additionally or alternatively, the blown balloon 24 may bepreferentially stretched to form a thinner distal tapered portion 38,thus creating the same or similar effective “strength differential” asmight be achieved via a thicker proximal tapered portion 36.

In yet another alternative embodiment, proximal tapered portion 36 mayinclude multiple rigidity features, such as longitudinally oriented ribs(not pictured). Such ribs may be formed, for example, during theblowing/dipping balloon formation process, by adding grooves in amandrel used to form balloon 24. Alternatively, ribs may be added afterballoon formation by applying axial lines of adhesive or other materialthat bond to the outer surface of balloon 24. Examples of such materialsmay include, but are not limited to, UV cure adhesive and polyurethane,nylon, and polyether block amide dissolved in a solvent solution.Alternatively, ribs made from polymer or metal strips may be bonded tooutside of balloon 24. Ribs may be made out of a variety of materialsand may provide additional proximal eversion resistance throughincreased thickness and/or by using a material of increased rigidity,stiffness and/or durometer.

FIG. 2A illustrates the fact that an optional feature of system 10 isone or more irrigation ports, apertures, openings or the like (notvisible in the drawing) for providing irrigation fluid 40 at or near thedistal end of system 10. Irrigation fluid 40 may serve the purpose, forexample, of helping clean the lens of camera 22, clear the field ofvision of camera 22, lubricate contact between system 10 and a ureteralwall and thus reduce friction during stone removal, and/or reduce painin the case where lidocaine or some other anesthetic is infused into thesite. In various embodiments, for example, fluid 40 may exit out of adistal end of system 10 via one or more small apertures in balloon 24(for example laser-drilled holes that allow fluid to slowly weep out ofballoon 24), via an irrigation lumen formed as a space between the innershaft and the retention member shaft, between camera 22 and the innershaft, or between the inner shaft and wall protection member shaft 42,or any other suitable fluid lumen or aperture(s). It may beadvantageous, for example, to provide irrigation fluid close to thedistal end of the camera, for clearing the field of view of the camera.This may be achieved, in some embodiments, by passing irrigation fluidthrough a space between the inner shaft and the retention member shaft.

Typically, only a low pressure of less than 1 atm is used to inflateballoon 24. This low pressure inflation enhances the ability of balloon24 to invaginate and in some embodiments to be advanced around theobstruction. Lower pressures are also advantageous in preventingureteral trauma associated with higher pressure and/or balloondiameters.

Once the obstruction is enveloped, it may often be easiest to remove theobstruction with balloon 24 partially or entirely deflated. In oneembodiment, using the constant force of a passive syringe, coupled withremoval system 10 and balloon 24 (via balloon inflation port 26), it ispossible to allow balloon 24 to deflate automatically due to the forceplaced on balloon 24 when basket 20 and stone S are pulled back intoballoon 24. In other words, the force and volume of basket 20 and stoneS being pulled into balloon 24 reduces the capacity of balloon 24 tohold fluid volume, which in turn pushes the fluid back up the ballooninflation lumen toward balloon fill port 26 and an attached syringe (orother fluid infusion source). In the case where the infusion source is asyringe, this fluid pressure will be sufficient to push an unobstructedsyringe plunger back, allowing balloon 24 to passively deflate. Otherconfigurations employing stop valves and/or pressure monitoring are alsopossible, in alternative embodiments.

In some embodiments, to aid in detection, it may be beneficial to expandthe ureter between the obstruction and the removal device. Inparticular, if the ureter is collapsed, then expanding it allows forbetter visualization. In the ureter, for example, about 1-2 cc of fluidcan often provide a small amount of passive dilation (about 1-3 mm in anaturally closed orifice), which allows greater obstructionvisualization. The dilation fluid used may be water, saline, or acombination of either with an analgesic agent. The fluid may beintroduced into the lumen/vessel in a variety of ways. For example, akidney stone removal device may emit a layer of fluid through relativelylow-flow rate nozzles to dilate the ureter (“hydrodilation”). In variousembodiments, for example, the flow rates used may be less than 20cc/min. This fluid buffer/hydrodilation may be used, for example, toprevent body luminal wall trauma during obstruction removal. A number ofnozzle profiles and hydrodilation techniques are described in patentapplication Ser. No. 13/761,001, which was previously incorporated byreference. The infused liquid (or liquids) may include water, saline,lidocaine and/or other suitable liquid(s).

Additional dilation may also be achieved through small perforations inballoon 24, in some embodiments. Perforations on the order of 0.006″ orsmaller provide adequate dilation without necessarily flooding the lumenwith fluid. In the case of the ureter, this implies minimizing renalpressure. Additionally, small perforations combined with a compliantballoon material allow for the perforations to effectively “seal” underlower pressures, allowing balloon 24 to inflate to a relatively lowpressure without liquid leakage. As the pressure is increased, theballoon diameter and fluid pressure increase, allowing liquid to passthrough the perforations and into the surrounding ureter or othervessel. This configuration may be advantageous for several reasons.First, it may help prevent over-inflation of balloon 24, by acting as apressure release mechanism. Second, the released fluid may act as alubricant, which will further facilitate stone removal. Third, theapertures may facilitate invagination of balloon 24.

A similar perforated design could be used in a non-compliant surfacewith smaller perforations. In this case, the increased water pressurealone would force the liquid from the non-compliant structure. In suchembodiments, portions of the device on which it may be advantageous toadd perforations include the instrument shaft, grasper shaft, or innerlumen side-wall, among others.

In various alternative embodiments, a smaller amount and/or flow rate offluid may be introduced, for example to enhance visualization. This typeof fluid introduction/irrigation may provide some amount of passive orslight dilation of the ureter but is not typically designed to providehydrodilation.

With reference now to FIGS. 3A and 3B, one embodiment of system 10 isillustrated in side cross section and end-on cross section,respectively. Number labels for the components of system 10 are carriedover to FIGS. 3A and 3B from those prior figures. Furthermore, neitherFIGS. 3A and 3B nor any prior or subsequent figures are necessarilydrawn to scale. Referring again to FIGS. 3A and 3B, and moving fromoutside to inside, system 10 first includes outer shaft 16, which isattached at its distal end to proximal attachment portion 35 of balloon24, and wall protection member shaft 42 (or “balloon shaft”), which isattached at its distal end to distal attachment portion 39 of balloon24. Moving inward, the next component is an inner shaft 44, which hasbeen referred to above but is not visible on previous figures. The nextshaft moving inward is a retention member shaft 46, which extendsdistally into basket 20. As discussed above, retention member shaft 46and basket 20 (or “stone retention portion”) may be referred to hereingenerally as a “stone retention member.” In some embodiments, such asthe one illustrated in FIGS. 3A and 3B, the stone retention member isone piece, with retention member shaft 46 extending from a proximal endof system 10 to basket 20 at its distal end. In other embodiments, aseparate retention member shaft piece may be attached to a separatestone retention portion piece to form the stone retention member.

Camera 22 is housed coaxially within retention member shaft 46, so thatits distal end faces into basket 20. In at least one embodiment, camera22 and inner shaft 44 are both fixed to handle 12, such that the distalend of camera 22 is positioned at or near the distal end of inner shaft.Retention member shaft 46, in this embodiment, is free to slideproximally and distally over camera 22 and within inner shaft 44. Thisallows basket 20 to be advanced out of, and pulled back into, innershaft 44, while keeping camera 22 in a fixed position, thus reducingwear and tear on camera 22.

Some of the components of system 10 are movable, relative to othercomponents. One embodiment is described here, but this is only one of anumber of potential embodiments. In alternative embodiments, movement ofcomponents may be entirely or partially changed, without departing fromthe scope of the invention. In one embodiment, outer shaft 16 may befixed to handle extension 14 and thus may slide back and forth relativeto handle 12 as handle extension 14 slides back and forth. Wallprotection member shaft 42 may be attached to a slider on handle 12 orhandle extension 14. In some embodiments, wall protection member shaft42 may tightly contact the inner wall of outer shaft 16 and may simplymove in conjunction with outer shaft 16 via friction force and/or mayslide proximally when the stone and basket 20 are pulled into balloon24. As mentioned above, inner shaft 44 may be fixedly coupled withhandle 12, so that it does not move relative to handle 12. Finally,retention member shaft 46 (or “basket shaft”) may be coupled proximallywith slider 32 on handle 12, so that retention member shaft 46 may beadvanced to advance basket 20 out of inner shaft 44. Inner shaft 44, inturn, may be exposed out of the distal end of outer shaft 16 by pullingback on handle extension 14 to pull outer shaft 16 proximally relativeto inner shaft 44. In one embodiment, system 10 may be advanced throughthe ureter with inner shaft 44 extended out of the distal end of outershaft 16. Alternatively, outer shaft 16 may be retracted later in theprocess, for example when system is already advanced to a treatmentlocation, to expose inner shaft 44. Either way, the entire system 10 maythen be advanced, once inner shaft 44 is extended out of outer shaft 16,to pass the distal end of inner shaft 44 around and past the stone.Basket shaft 46 may then be advanced to expose basket out of the distalend of inner shaft 44. The whole system 10 may then be retracted to trapthe stone in basket 20. Camera 22, meanwhile, may be fixedly, thoughremovably, coupled with handle 12, so that it remains in a fixedposition relative to the moving components during the process. These andother steps of one method embodiment will be described in further detailbelow.

A mentioned previously, wall protection member shaft 42 may be mobilerelative to outer shaft 16. For example, it may be possible to retractwall protection member shaft 42 as basket 20 and stone are pulled backinto balloon 24. Alternatively or additionally, wall protection membershaft 42 may passively move back as basket 20 and stone are pulled intoballoon 24. Moving at least some of the components of system 10 relativeto other components allows kidney stone removal (or other obstructionremoval from other body lumens) using the method briefly described aboveand described in more detail below. The various components may be madeof any suitable materials, such as flexible polymers.

As mentioned above, this combination of moving parts of system 10 may bealtered in alternative embodiments. For example, it may be possible inone embodiment to fix outer shaft 16 to handle 12 and have inner shaft44 slide in and out of outer shaft 16. This is just one potential changethat might be made, and the embodiment described here is simply toprovide an example.

FIGS. 4A-4E illustrate one embodiment of a method for using system 10 toremove a kidney stone from a ureter (or other obstructions from otherlumens, in alternative embodiments). FIGS. 4A-4E are not drawn to scale.First, as illustrated in FIG. 4A, the distal end of the kidney stoneremoval system 10, here shown as outer shaft 16 and balloon 24, isadvanced into a ureter U to a position near a kidney stone S, just belowthe obstruction. Shaft 16 and balloon 24 may be advanced through anysuitable endoscope device, steerable shaft, catheter or other introducerdevice, such as but not limited to a cystoscope (not shown). In someembodiments, camera 22 may be used to visualize/detect the kidney stoneS and monitor advancement of system 10 to a desired location in theureter U relative to the stone S. Next, as illustrated in FIG. 4B,balloon 24 may be inflated, which may help maintain a position of shaft16 in the ureter U. Then, inner shaft 44, containing basket 20,retention member shaft 46 and camera 22, is advanced past the stone S.Camera 22 may be used to visualize this advancement as well.

As shown in FIG. 4C, basket 20 may next be advanced out of inner shaft44, allowing basket 20 to expand. Again, camera 22 may be used tovisualize advancement and expansion of basket 20. Next, as illustratedin FIG. 4D, basket 20 may be drawn back proximally (retracted towardouter shaft 16) to capture the stone S by retracting the entire system10. This step may also be visualized using camera 22. Finally, asillustrated in FIG. 4E, the stone S and basket 20 may be pulled backinto balloon 24, by pulling retention member shaft 46 proximally, thuscausing balloon 24 to invaginate and at least partially surround thestone S. Balloon 24 will help prevent damage to the wall of the ureteras the stone S is removed, by enveloping the sharp edges of the stone Sand thus providing a low-friction surface. The stone S may then beremoved by pulling shaft 16 and balloon 24 out of the ureter. Due to thelocation of camera 22 at or near the distal end of inner shaft 44, anyor all of these steps may be visualized via camera 22.

One optional step may involve dilating one or more areas of the ureterby inflating balloon 24 at any point during the stone capture and/orstone removal process. This may be useful, for example, if the system 10is being removed from the ureter and a constricted or narrowed area isencountered. In one embodiment, balloon 24 may be inflated to dilate atsuch an area, and then the inflation device, such as a syringe, may beused to actively deflate balloon 24 partially, or alternatively it maysimply be allowed to automatically retract to deflate balloon 24 to anominal pressure for continued removal of system 10 from the ureter.

In some embodiments, handle 12 may include a coupler for coupling camera22 with inner shaft 44, so that camera 22 is always located at the tipof the inner shaft 44. This ensures full visualization, while preventinghaving camera 22 protrude beyond the distal end and thus risk beingdamaged. Some embodiments may also include a frictional fit of basket 20in inner shaft 44, such that basket motion will be coupled to camera 22and shaft 44 when not actively controlled by the user, thus eliminatingthe need to move two sliders at once, while de-coupling the two whenactive, independent basket control is required. Other unique features ofhandle 12 are the dual-slider configuration and overall handle shape,which allow single-handed actuation. Yet another feature is the ballooninversion/invagination that is caused by sliding retention member slider32 until the captured stone is pulled against the tip of wall protectionmember shaft 42. Further motion of basket slider 32 causes wallprotection member shaft 42 to slide proximally relative to thestationary outer shaft 16, which in turn causes balloon 24 toinvaginate/invert. This design eliminates the need for an additional“invagination slider.” In some embodiments, however, wall protectionmember shaft 42 will, in fact, be attached to a slider. In someembodiments, this slider may be used to return balloon 24 to itsoriginal pre-invagination shape. Such a slide may also be used, ofcourse, to invaginate balloon 24 if necessary.

With reference now to FIGS. 5A-5F, another embodiment of a method forremoving a kidney stone using system 10 is illustrated. In thisembodiment, as illustrated in FIG. 5A, the distal end of the kidneystone removal system 10 is advanced through a ureter U with inner shaft44 already extended out of the distal end of outer shaft 16 and withballoon 24 deflated. As illustrated in FIG. 5B, all of system 10 maythen be advanced further, to position a distal end of inner shaft 44past the stone S. Still, balloon 24 is in a deflated configuration. Asshown in FIG. 5C, basket 20 may next be advanced out of inner shaft 44,allowing basket 20 to expand. Next, as illustrated in FIG. 5D, basket 20may be drawn back proximally (retracted toward outer shaft 16), byretracting the entire system 10, to capture the stone S. At this point,as illustrated in FIG. 5E, balloon 24 may be inflated. Finally, as shownin FIG. 5F, basket 24 and stone S may be pulled back into balloon 24.

In some cases, this embodiment of the method may be simpler and/oreasier to perform than the embodiment described previously. As should beevident from these embodiment descriptions, however, any given methodembodiment may include any suitable number of steps and order of steps.Some steps may be eliminated and/or added in various alternativeembodiments, without departing from the scope of the invention.

With reference now to FIGS. 6A and 6B, in an alternative embodiment, akidney stone removal system 110 may include an end effector 118 that hasa compliant funnel 124 (or “obstruction shaft”), rather than a balloon,to provide protection for the ureteral wall. End effector 118 may alsoinclude an expandable basket 120, a camera 122 and one or moreirrigation ports for providing irrigation fluid 140. System 110 mayinclude an outer shaft 116 and some or all of the other componentsdescribed above in relation to other embodiments. Due to thesubstitution of funnel 124 for a balloon, however, the design of system110 may be somewhat simpler. For example, system would not include awall protection member shaft or a balloon inflation port. Funnel 124acts in the place of the balloon as a guard against ureter wall traumaduring stone removal. As such, funnel 124 may be made of any suitablepolymer or other material that helps reduce or minimize friction and/orthat can serve as a protective layer to reduce trauma from sharp edgesof kidney stones. As illustrated in FIG. 6B, basket 120 and stone S maybe drawn back proximally into funnel 124, just as in the embodiment withthe balloon, except that funnel 124 does not invaginate or invert.Camera 122 may be positioned at or near the distal end of funnel 124,for visualizing the removal procedure. In alternative embodiments,funnel 124 may be replaced with any other suitable protective,friction/trauma reducing device, such as a shaft, cup, sock, lubricatedsurface or the like. Optionally, system 110 may include additional portsor apertures, for example at or near the juncture of funnel 124 andshaft 116, for providing lubricating fluid to further facilitate stoneremoval.

Expandable basket 120 may have a shape that facilitates the expansion ofcompliant funnel 124 around the stone S and basket 120. As illustratedin FIG. 6A, in some embodiments, expandable basket 120 may have atapered shape from the portion that retains the stone S toward theconnection of basket 120 with the basket shaft (not shown). The taperedshape may help align and expand compliant funnel 124 around the kidneystone S or other obstruction. The expansion of basket 120 may also beused to expand compliant funnel 124 around the obstruction. Using basket120 to expand complaint funnel 124 makes funnel 124 a passive component,reducing overall complexity of system 110.

Prior to use, complaint funnel 124 often needs to be retained in such away that it does not catch or rub on either the working channel of theintroducing device (cystoscope or other endoscope, for example) or thewall of the body lumen during advancement. One solution would be toprovide system 110 with an outer shaft that can slide over funnel 124 toprevent it from expanding prior to capturing the obstruction. Due tospace constraints, however, it may be advantageous to eliminate anexternal shaft from the device assembly. One such solution is to invertfunnel 124 inside outer shaft 116 around basket 120 during advancementto the obstruction. When basket 120 is advanced out of the mainassembly, funnel 124 is deployed into position (as in FIG. 6A). Avariety of variations to this deployment method using other aspects ofcatheter assembly (camera lumen or fluid introduction lumen, forexample) may be possible and will all function in an essentiallyequivalent manner to the above embodiment.

The embodiments thus far have involved systems in which expandablebaskets are used to trap a stone and pull it back into a protectiveelement, such as a balloon or compliant funnel. A different group ofembodiments eliminates the expandable basket and instead traps the stoneor other obstruction from the side of approach of the device toward thestone. For example, these embodiments typically involve expandablegraspers or expandable funnels that are advanced directly over/aroundthe stone and thus used to pull the stone out of the ureter. Some ofthese embodiments may also involve the use of suction to help pull thestone into the grasper. Several examples of such embodiments aredescribed further below.

With reference now to FIGS. 7A and 7B, one example of an expandablegrasper 210 that may be used to retain a stone or obstruction mayinclude multiple struts 213, each having a hooked distal tip 214. Asillustrated in FIG. 7A, the struts 213 are typically joined together ata proximal end 215. (FIG. 7B is a close-up view of several struts 213and distal tips 214.) Expanding grasper 210 may include any suitablenumber of struts 213, and struts 213 may include any of a number ofdifferently shaped distal tips 214, according to various alternativeembodiments. In some embodiments, distal tips 214 of struts 213 ofexpandable grasper 210 may be folded inward to form hooks or “teeth,” tohelp retain the kidney stone within grasper 210. Typically, although notnecessarily, grasper 210 will be combined with some form of protectivecoating, membrane, balloon or other protective component to reduce orminimize trauma to the ureteral wall during stone removal. When grasper210 is advanced out of a shaft in which it is housed, it will expand toa diameter sufficient to grasp a kidney stone. When grasper 210 is thenat least partially retracted (drawn back) into the shaft, grasper 210will contract at least slightly to grasp and hold the kidney stone.

In some embodiments, expanding grasper 210 may be configured to expandautomatically when released from a shaft. In such embodiments, forexample, expanding grasper 210 may be made by shape setting Nitinol orpre-bending an elastic material such as spring steel or PEEK into thedesired expanded geometry. The geometry can then be elasticallycompressed into a much smaller (unexpanded) shape within the shaft (forexample, catheter shaft having a diameter of 6 French or smaller).Expanding grasper 210 may be deployed by advancing grasper 210 out ofthe shaft and/or sliding the shaft back from the grasper 210. Bothresult in less constraint on the grasper 210, causing struts 213 tospread apart at their distal ends, thus increasing the diameter of thedistal end of grasper 210.

Referring to FIGS. 8A and 8B, another alternative embodiment of a stoneremoval device 220 may include an outer shaft 216, an expandable grasper226, with multiple struts and curved distal tips 228, and a protectivemembrane 224 positioned around grasper 226. FIG. 8B shows device 220 inplace within a ureter U and partially surrounding a kidney stone S. Invarious embodiments, membrane 224 may be made of any suitable polymer orother flexible material and may be configured to prevent trauma to aninner wall of the ureter U once the kidney stone S is captured therein.In various embodiments, membrane 224 may be one layer of material,multiple layers of material, an inflatable balloon, a funnel, a cup, asock or the like. In some embodiments, grasper 226 and membrane 224 maybe housed within outer shaft 216 during advancement of device 220through the ureter, and then advanced out of the end of outer shaft 216to expand and then trap a kidney stone S. In some embodiments, and withreference to FIG. 7B, grasper 226 and membrane 224 may expand until theymatch or slightly exceed the horizontal diameter of the kidney stone Sto be removed. In some embodiments, grasper 226 may be advanced out ofouter shaft 216 by an amount that achieves a desired diameter.

FIG. 8B illustrates part of a method for removing a kidney stone S froma ureter U, using removal system 220. As illustrated here, system 220 isadvanced to a location in the ureter U adjacent the stone S. Expandablegrasper 226 is then advanced out of outer shaft 216 (and/or outer shaft216 may be retracted back from grasper 226), to allow grasper 226 toexpand to its expanded, default configuration, such that distal tips 228are configured in a diameter as wide or wider than the stone S. Grasper226 may then be advanced over the stone S, thus capturing the stone S ingrasper 226. Protective membrane 224 acts to protect the inner wall ofthe ureter U while removal system 220 is used to pull the stone S out ofthe ureter U.

In some embodiments, a kidney stone removal system may include, or maybe used in a system including, a mechanism for dilating the ureter. Forexample, in one embodiment, a stone removal system may include a balloonthat encases grasper 210 or 226. The balloon may be infused with air,water, saline, a biocompatible lubricant, a local anesthetic (such aslidocaine), any other suitable substance, or a combination of any ofthese substances, to achieve a desired viscosity, cost, and/orperformance. The balloon may provide a smooth surface around theobstruction, reducing removal friction and facilitating passage. Inaddition, the balloon can be integrated in such a way that inflationcauses an additional retention force on the obstruction by inflating theside of the balloon on the inside of struts around the stone.

In alternative embodiments, dilation of the ureter (or other body lumenin other embodiments) may be performed via hydrodilation, without theuse of a balloon. Numerous embodiments of devices and methods forhydrodilation of body lumens, such as the ureters, are described inpending U.S. patent application Ser. No. 13/716,001 (Pub No.2013/0165944), entitled “Apparatus, Systems, and Methods for RemovingObstructions in the Urinary Tract,” the full disclosure of which ishereby incorporated by reference herein. Many of the embodimentsdescribed in the above-reference patent application use jets to propelfluid against the wall of the ureter to provide hydrodilation. Theseembodiments may be combined with the embodiments described herein, suchthat the hydrodilation jets may be used to dilate up and around a kidneystone from the proximal end (or “base”) of an expandable grasper, forexample. Alternatively, in one embodiment, hydrodilation may be achievedby ejecting fluid out of hollow tines of an expandable grasper (notillustrated)—i.e., using hollow grasping members as water channels withholes near the tips for water ejection.

Referring to FIG. 9, in another alternative embodiment, a kidney stoneremoval device 230 may include an expandable grasper having multiplestruts 234 with hooked distal tips 238, a dilation balloon 232 coupledwith struts 234, and a shaft 236 for containing the grasper and balloon234 during delivery into the ureter. Dilation balloon 232 may includemultiple apertures 240 (or “holes” or “perforations”) to allow fluid 242to pass from balloon 232 into the region around the obstruction. Forexample, a local anesthetic may be used to numb the region around theobstruction, a lubricant may be desired for further reduction offriction around the stone, and/or any of the fluids mentioned above maybe used to provide hydrodilation force around balloon 232 to reducefriction and/or tissue trauma.

In the embodiment illustrated in FIG. 9, balloon 232 is positioned onremoval device 230 on the outside of struts 234. Balloon 232 may beinfused with air, water, saline, a biocompatible lubricant, a localanesthetic (such as lidocaine), any other suitable substance and/or acombination of substances. Attaching balloon 232 to the outside surfaceof struts 234 allows struts 234 to have hooks 238 (or teeth, etc.) toincrease the retention force on the stone, without risk of balloonperforation.

Referring now to FIG. 10, as mentioned above, any of the embodiments ofobstruction removal devices described herein may include, or may be usedwith a system that includes, one or more obstruction detectioncomponents. These obstruction detection components may be specificallyconfigured for kidney stone detection in some embodiments. FIG. 10illustrates another embodiment of a kidney stone removal device 250,including an expandable grasper having multiple struts 254 with hookeddistal tips 258, a compliant membrane 252 coupled with struts 254, onehollow strut 262, a small camera 260 extending through the lumen ofhollow strut 262, and a shaft 256, which the other components areadvanced out of and retracted back into. In one embodiment, for example,hollow strut 262 may have a lumen with an inner diameter of about 0.4mm. This lumen is large enough for a small fiber camera 260 to visualizea kidney stone directly. Illumination for small fiber camera 260 may beprovided, in some embodiments, around the sides of camera 260.Alternatively, illumination may be provided via a light source, such asa fiber, directed through a central lumen of shaft 256. In variousalternative embodiments, fiber camera 260 may be either reusable ordisposable. In other alternative embodiments, an inductance coil orimpedance sensor may be included for detection purposes, for example foruse in smaller lumens.

Referring now to FIGS. 11A and 11B, in another embodiment, a kidneystone removal device 270 may include an expandable mesh grasper 272,positioned inside an inflatable balloon 274 (or alternatively a membraneor other friction reducing/protective member), and a shaft 276 forhousing both. In one embodiment, expandable mesh grasper 272 may be madeof a shape-memory material and may have a configuration similar to thatof a vascular stent. Grasper 272 may be constructed from a number ofhighly compliant materials, such as Nitinol, spring stainless steel, orPEEK plastic, among others. The geometry can then be elasticallycompressed into a much smaller (unexpanded) shape within shaft 276 (forexample, a 6 French catheter shaft). Grasper 272 may then be deployed byadvancing grasper 272 out of shaft 276 and/or sliding shaft 276 backfrom the grasper 272. Either of these methods results in reducedconstraint on the expandable member 272, causing the tip diameter toincrease. This diameter can then be expanded until it matches thehorizontal diameter of the stone. In some embodiments, the tips ofexpandable grasper 272 may be turned/folded inward to form “teeth” tohelp retain the stone, similar to the hooks/teeth described above. Asmentioned above, in various alternative embodiments, expandable grasper272 may be combined with any other suitable protective member in placeof balloon 274.

Referring to FIG. 11B, in some embodiments, balloon 274 may be infusedwith air, water, saline, a biocompatible lubricant, or a localanesthetic (such as lidocaine). A combination of any of the above mayalso be used to achieve a desired viscosity, cost, clinical performance,functional performance, and/or the like. Balloon 274 creates a smoothsurface around the obstruction, reducing removal friction andfacilitating passage. In addition, balloon 274 may be integrated in sucha way that inflation causes an additional retention force on the stonebuy inflating the side of balloon 274 on the inside of mesh grasper 272around the stone. As described above in relation to other embodiments,balloon 274 may also include apertures or perforations to allow fluid topass from balloon 274 into the region around the obstruction. Forexample, a local anesthetic may be used to numb the region around theobstruction, a lubricant may be desired to reduce the friction of theobstruction on the surrounding wall, or any of a number of fluids may beused to provide a hydrodilation force around balloon 274 to reducefriction and/or tissue trauma.

As illustrated in FIG. 11B, in some embodiments, balloon 274 may bepositioned on the outside surface of mesh grasper 272. Having theballoon attached solely to the outside surface of balloon 274 allowsgrasper 272 to have “teeth” to increase the retention force on the stonewithout risk of balloon perforation.

Referring now to FIG. 12, in another alternative embodiment, a stoneremoval device may include an expandable mesh grasper 280 that includesa mesh 282 and webbing 284 disposed between or over mesh 282. Webbing284 may comprise a highly complaint material, which may be applied tomesh 282 via a dipping process, for example, thus forming a smoothsurface for the natural dilation created by grasper 280, and thusreducing the friction required for obstruction removal. In oneembodiment, a hydrodilation fluid may be emitted from a portion ofwebbing 284. Alternatively, hydrodilation fluid may be provided usingany of the methods described above. In one embodiment, webbing 284 mayserve as the protective element, eliminating the need for an additionalelement, such as a balloon, funnel-shaped membrane or the like.

Referring now to FIGS. 13A and 13B, a distal portion of anotheralternative embodiment of a kidney stone removal device 290, including aprotective balloon 292 is illustrated. Device 290 may include balloon292, an outer shaft 298, and an inner shaft 296 that moves in and out ofshaft 298. Balloon 292 may include a distal tapered portion 293 and aninner, stone entrapment space 294. When inner shaft 296 is fullyadvanced, stone entrapment space 294 is rolled outwards and becomestapered portion 293 (as in FIG. 13A). When inner shaft 296 is pulledback/retracted proximally, back into outer shaft 298, tapered portion293 rolls inward (or “invaginates”) to form stone entrapment space 294.

In one embodiment, a method for using device 290 may involve advancingthe distal end of device 290 into the ureter to a position near a kidneystone. Balloon 292 may then be partially inflated and then advancedaround the obstruction from the direction of approach of device 290,such that the kidney stone becomes trapped in entrapment space 294.Balloon 292 may then optionally be inflated further, using any suitableinflation medium provided via a central lumen or specified inflationlumen(s) of shaft 298. This method of approaching and capturing thekidney stone is advantageous, because it eliminates the complexity ofmanipulating the device past the obstruction. This embodiment of device290 may also reduce body lumen trauma and friction that results from thecatheter lumen placement adjacent to the stone. Balloon 292 (or othercomplaint material member in alternative embodiments) will typicallyhave a tapered shape and thickness configured to facilitate envelopingthe stone without necking or forcing the stone out of balloon 292 duringdeployment. In various embodiments, for example, balloon 292 may includea tapered portion at its distal end with an angle of between about 2degrees and about 45 degrees.

FIG. 13A shows device 290 with inner shaft 296 extended out of shaft 298to its maximum extent. FIG. 13B shows inner shaft 296 retracted to pullback on the distal end of balloon 292, thus forming entrapment space294. In some embodiments, balloon 292 may be rolled over a stone orother obstruction by retracting inner shaft 296 and advancing outershaft 298. Alternatively, it may be possible to achieve the same orsimilar effect by only retracting inner shaft 296 or only advancingouter shaft 298. Whichever method is used, entrapment space 294 may beformed to entrap the kidney stone for removal.

With reference now to FIG. 14A, in an alternative embodiment, a kidneystone removal device 300 may include a balloon 302, an outer shaft 308,and an inner shaft 306 that moves in and out of shaft 308. Balloon 302may include an inner, stone entrapment space 304 and a distal, taperedportion 303. Inner shaft 306 may include a rigid, distal ring 307 orplatform, which connects shaft 306 to the inside edge of a slightlyinverted balloon 302. The outside of balloon 302, attached to movableinner shaft 306, can be extended around the kidney stone or otherobstruction. Ring 307 may be positioned to sit on the bottom of thestone/obstruction, and balloon 302 may be advanced around the stone toenclose the stone in entrapment space 304. Ring 307 may help prevent thebottom portion of the inverted balloon 302 from “necking down,” whichmay help facilitate obstruction entrapment by balloon 302. Thephenomenon of “necking down” refers to the narrowing of balloon 302 inthe area where it connects to shaft 66, which can be seen in FIG. 13B.

With reference now to FIG. 14B, an alternative embodiment of a stoneremoval device 300′ with a differently shaped ring 307′ is illustrated.In all other ways, device 300′ is the same as shown in FIG. 14A andincludes a balloon 302′ with a tapered portion 303′ and an inner space304′, an outer shaft 308′, and an inner shaft 306′ that moves in and outof shaft 308′. In this embodiment, ring 307′ may have an atraumaticconfiguration so that when inner shaft 306′ is fully advanced, ring 307′will not inadvertently damage other structures. In one embodiment, atapered complaint material could be attached to the tip of balloon 302′to increase the rigidity of the tip section relative to balloon 302′.This tapered section will provide additionally rigidity to the tip, andcan prevent balloon 302′ from necking down to a small diameter as it isdeployed over the obstruction, similar to the function of ring 307′ atits attachment with balloon 302′. This material may also serve as anatraumatic trip during catheter deployment, and may be superior in thecase of tapered balloon 302′, as it will conform to the balloon shape.

In any of the above-described embodiments, suction force may be used tohelp draw a kidney stone or other obstruction into the entrapment spacein the balloon. In some embodiments, suction force may be applied via acentral lumen in the inner shaft of the obstruction removal device, sothat the suction force is applied directly inside the entrapment spaceof the balloon.

It is possible to combine any of the above-described removal methods. Acombination of the above may be preferable in some embodiments,depending on the obstruction location, size, required retention forceand/or other factors.

In all the embodiments described above in relation to FIGS. 13A, 13B,14A and 14B, the retention member, namely the balloon, also acts as thewall protection member. The two-sided complaint material, which isdescribed above as a balloon but which may have other configurations inalternative embodiments, may be partially infused with air, water,saline, a biocompatible lubricant, or a local anesthetic (such aslidocaine) then rolled or linearly extended past the stone. In someembodiments, as mentioned above, the dilation balloon may be perforatedto allow at least some of the fluid to pass into the region around theobstruction. For example, a local anesthetic may be used to numb theregion around the obstruction, a lubricant may be desired to reduce thefriction of the obstruction on the surrounding wall, or the fluid may beused to provide a hydrodilation force around the balloon to reducefriction and/or tissue trauma.

Any of the embodiments described above in relation to FIGS. 13A, 13B,14A and 14B may also include some form of visualization component. Insome embodiments, for example, a visualization device may extend througha central lumen of the moveable inner shaft, thus providingvisualization into the entrapment space of the balloon. In a 6Fcatheter, a typical size deployed through the working channel of anendoscope, this inner lumen could be upwards of 1 mm (3 F). This wouldallow both a light source and fiber camera to be deployed down thecentral lumen for visualization.

In some embodiments, a stone removal system may be configured withoutone or more of the previously-described shafts. Such embodiments mayhave a simpler design than that of previously-described embodiments,which may facilitate simpler articulation of the device and reducedoverall complexity. Further, such embodiments may have a smallerdiameter, which may provide advantages in deployment and usage, such asreduced procedure times, reduced cost, and increased usability.

FIGS. 15A and 15B illustrate one alternative embodiment of a stoneremoval system 410. Stone removal system 410 and its components mayinclude characteristics of the previously described stone removalsystems, including but not limited to those shown and described withregard to FIGS. 3A and 3B. For example, stone removal system 410 mayinclude an outer shaft 416, a retention member 420, a camera 422, a wallprotection member 424, an inner shaft 442 and a retention member shaft446. Wall protection member 424 may be connected between outer shaft 416and inner shaft 442. An attachment point 443 between inner shaft 442 andwall protection member 424 may be located at approximately distance daway from a distal end of inner shaft 442. In some embodiments, stoneremoval system 410 may include one fewer shaft than device 10 of FIGS.3A and 3B. Such embodiments may facilitate a reduction in diameter ofouter shaft 416 by approximately 1 French (approximately 0.33 mm),compared to device 10.

In some embodiments, one or more shafts may have multiple functions,thereby facilitating a reduction in the total number of shafts. Forexample, inner shaft 442 may act as a sheath for retention member 420and may have attachment point 443 for wall protection member 424. Insome embodiments, a distal portion of wall protection member 424 may beattached to a distal portion of inner shaft 442 at attachment point 443.Attachment point 443 may be located at a number of different locationson inner shaft 442, such as on an inner surface or an outer surface ofinner shaft 442, proximally spaced from the distal end of inner shaft442, or at the distal tip of inner shaft 442. In the embodiment shown inFIG. 15A, attachment point 443 is located on an outer surface of innershaft 442, proximally spaced from the distal end of inner shaft 442 bydistance d. Locating attachment point 443 on an outer surface of innershaft 442 may help avoid interference with deployment of retentionmember 420, as compared to an embodiment in which attachment point 443is located on the inner surface of inner shaft 442. Further, spacingattachment point 443 by distance d may advantageously allow for the tipof system 410 to be advanced past a stone without having to also advancewall protection member 424 past the stone. Distance d may be selected toprovide sufficient distance for the distal end of inner shaft 442 to beadvanced past a stone with additional distance to allow some margin formanipulation of system 410. In some embodiments, for example, distance dmay be about 5 mm to about 20 mm, or more ideally about 5 mm to about 15mm, or even more ideally about 5 mm to about 6 mm. In some embodiments,it may be advantageous for distance d to be no longer than necessary toadvance the distal end of inner shaft 442 past a stone without alsoadvancing attachment point 443 to or past the stone. Shorter distances dmay make balloon invagination easier because, in some embodiments,increasing distance d may correspondingly increase the distance thestone is retracted before it reaches wall protection member 424. Shorterdistances d may also facilitate use and manipulation of system 410 whenused with a ureteroscope, because it may allow for a shorter portion ofsystem 410 to be advanced out of the distal end of the scope.

FIGS. 16A and 16B illustrate another alternative embodiment of a stoneremoval system 510, including an outer shaft 516, a retention member520, a wall protection member 524, an inner shaft 542, and a retentionmember shaft 546. The configuration of stone removal system 510 of FIGS.16A and 16B may facilitate a reduction in size of stone removal system510 compared to other embodiments. Wall protection member 524 may beconnected between outer shaft 516 and inner shaft 542, and there may bean attachment point 543 between inner shaft 542 and wall protectionmember 524 located at approximately distance d away from distal tip ofinner shaft 542. In some embodiments, stone removal system 510 may havea diameter of approximately 3 French (approximately 1 mm). Someembodiments do not include a camera inserted through retention membershaft 546. This enables retention member shaft 546 to be configured witha reduced size. In addition, retention member shaft 546 may beconfigured as one or more wires or solid shafts as opposed to, forexample, a tubular luminal structure. This further enables reduction ofdiameter of outer shaft 516.

Using one or more designs described above (e.g., by removing a camera),the catheter diameter (e.g., the diameter of outer shaft 516) may bereduced to approximately 3 F (1 mm) in diameter, between approximately 2F and 6 F in diameter, or other sizes. The overall diameter of stoneremoval system 510 may be selected based on a particular working channelthrough which it may be fed. Some embodiments may be configured suchthat a catheter may operate with existing 3 F to 4 F working channelendoscopes, such as flexible ureteroscopes, which may have a workingchannel with a size of approximately 3.4 F, approximately 3.2 F toapproximately 3.8 F, or other sizes. In another example, stone removalsystem 510 may be adapted to be fed through the working channel of acystoscope that has a working diameter of approximately 6 F to 8 F. Someembodiments may be operated in conjunction with ancillary visualizationsuch as direct vision provided by a uretersope or fluoroscopy. Suchancillary visualization could be used in addition to or instead ofdirect visualization provided by the embodiment itself

In some embodiments, a stone removal system (e.g., stone removal system410 or stone removal system 510) may include a guide wire, laser fiber,or other component. Such components may be in addition to or instead ofa camera (e.g., camera 422).

For example, a system may include a guide wire port and a lumencompatible with a guide wire (e.g., a standard size guide wire, such asa 0.018″ diameter guide wire). The guide wire may facilitate the use ofthe system to with fluoroscopy. In some embodiments, the guide wire mayrun coaxially with the other components of the system to a stoneretention member. In some embodiments, the guide wire may run adjacentto another component of the system, such as through a central lumen. Insome embodiments, a catheter of a system with a guide wire may have anouter shaft diameter of less than 1.2 mm (3.5 French), approximately 3.5F to 4 F, or approximately 4 F to 5 F.

As another example, a system may include a laser fiber port and a lumencompatible with a laser fiber. The laser fiber may be configured toapply laser energy to a stone or other target as part of, for example,laser lithotripsy. In some embodiments, the laser fiber may be a 100-200micron laser fiber. The system may include a lumen (e.g., a hypotube)having an inner diameter of approximately 0.005″ to 0.009″ toaccommodate the laser fiber. The laser fiber may run coaxially withother components of the system to a stone retention member. In someembodiments, the laser fiber may run adjacent to and/or coaxially withanother component of the system, such as through a central lumen. Thelaser fiber may be configured to allow an obstruction (e.g., a stone) tobe grasped and fragmented. This could help provide a more efficient useof an endoscope's working channel in embodiments where systems 410 and510 are deployed through a working channel of another endoscope.

Referring now to FIGS. 17 and 18A-18D, another embodiment of a stoneremoval device 600 is illustrated. In this embodiment, stone removaldevice 600 generally includes a handle 612 at the proximal end, an outershaft 616, and an end effector 618 at the distal end. As mentionedpreviously, for the purposes of this application, the term “endeffector” 618 is used generally to refer to a distal portion of stoneremoval device 600 that performs the functions of capturing andretaining a stone, protecting the ureteral or other lumen wall fromdamage during stone removal, and/or other functions. In variousembodiments, for example, end effector 618 may include retention member620 (in many embodiments an expandable, wire basket), a wall protectionmember 624 (in many embodiments an expandable balloon), and any distalportions of shafts or the like that might be connected to retentionmember 620 and/or wall protection member 624. (Note: in FIG. 17, only adistal tip of retention member 620 is shown, in a collapsed/non-expandedconfiguration. Retention member 620 is shown in an expandedconfiguration in subsequent figures.) For example, in the embodiment ofFIG. 17, inner shaft 642 may be considered part of end effector 618.However, the demarcation of which components or parts of device 600 areincluded in end effector 618 and which parts are not should not beinterpreted as limiting the scope of the application in any way.

Handle 612 is located at the opposite, proximal end of the stone removaldevice 600 from end effector 618. In this embodiment, handle 612includes an eversion mechanism and a retention member mechanism. In thisembodiment, the eversion mechanism is an eversion slider 602 and theretention member mechanism is a retention member slider 604. Inalternative embodiments, either slider 602, 604 (or both) may bereplaced by a lever, a knob, a wheel, a button, or any other suitablemechanism by which a user may manipulate handle 612 to actuate movementof wall protection member 624 and/or retention member 620. In general,eversion slider 602 operates to evert wall protection member 624, andretention member slider 604 operates to translate (advance and retract)retention member 620. Retention member 620 may be connected to aretention member shaft 646 (only visible in FIGS. 18B and 19B), which inturn is connected to retention member slider 604. Stone removal device600 may include any of the characteristics of the devices and systemsdisclosed herein, including but not limited to systems 410, 510.

Actuation of eversion slider 602 or retention member slider 604 maycause actuation of one or more shafts of device 600. Eversion slider 602may be configured to actuate wall protection member 624 to cause atleast partial eversion of wall protection member 624. The words “invert”and “evert” may be used interchangeably herein to describe theinvagination of a wall protection member 624 or other component(s)disclosed herein. Eversion slider 602 may be connected to inner shaft642 (to which wall protection member 624 may be attached), such thatactuation of eversion slider 602 causes movement of inner shaft 642relative to one or more of the other shafts. Retention member slider 604may be connected to retention member 620 and/or retention member shaft646, and actuation of retention member slider 604 may cause movement ofretention member 620 and/or retention member shaft 646 relative to oneor more of the other shafts. In some embodiments, the user may not needto directly employ either or both sliders 602, 604. Instead, forexample, the movement of other portions of stone removal device 600 mayprovide input to actuate slider 602 or 604, without the user directlymanipulating the mechanism. In some embodiments, when retention member620 is retracted back into wall protection member 624, with the stoneretained, wall protection member 624 may evert automatically, thus notrequiring the user to evert wall protection member 624 via eversionslider 602.

In various alternative embodiments, stone removal device 600 may includeone or more other mechanisms for actuating one or more other shafts orcomponents. For example, handle 612 may include one or more mechanismsconfigured to move outer shaft 616 and/or a camera or other componentinserted into a lumen of device 600. In other embodiments, handle 612may include a mechanism configured to move two or more of the shafts orother components. For example, handle 612 may include a mechanismconfigured to move any combination of two, three, four, or five or moreof outer shaft 616, wall protection member 624, inner shaft 642,retention member shaft 646, and/or other components.

In some embodiments, the components of device 600 may be adapted suchthat the components are kept stationary by a friction fit, and themovement of the mechanisms actuates one or more components and overcomesthe friction fit. In some embodiments, the friction fit may be createdin the fit between a mechanism and handle 612. In some embodiments, thefriction fit may be created in a fit between a gasket (e.g., a rubbergasket) and a mechanism or a shaft. In some embodiments, eversion slider602 is held stationary by friction through a seal used for a wallprotection member infusion port.

In some embodiments, the friction fit may be configured such thatretention member slider 604 and retention member shaft 646 arestationary relative to eversion slider 602 and inner shaft 642, suchthat a user needs to control only one mechanism at a time. The frictionmay be such that the user's hand can provide enough force to overcomethe friction and actuate retention member slider 604, but othermovements, such as the movement of eversion slider 602, would not resultin retention member 620 substantially moving relative to inner shaft642. In this manner, the user would not need to continuously preventmovement of retention member slider 604 during actuation of eversionslider 602. In some embodiments, the components of device 600 may beheld in position by a lock, and the movement of the mechanismsdisengages the lock and allows movement of one or more shafts.

In some embodiments, device 600 may be placed in an insertionconfiguration for inserting the distal end of the device into a lumen ofa patient and navigating to a target site. In this configuration,eversion slider 602 and retention member slider 604 may be in particularpositions. In one embodiment, eversion slider 602 may be in adistal-most position, and retention member slider 604 may be in aproximal-most position. In this configuration of sliders 602, 604,retention member 620 may be positioned within inner shaft 642, such thatretention member 620 is sheathed within inner shaft 642. In someembodiments, retention member 620 may be self-expanding, and theconfines of inner shaft 642 may prevent retention member 620 fromexpanding. The distal ends of outer shaft 616 and inner shaft 642 may bespaced apart, such that wall protection member 624 is in an insertionconfiguration. For example, in configurations where wall protectionmember 624 is a balloon, the balloon may be deflated to facilitateinsertion.

During a procedure, end effector 618 may be positioned near a targetsite (e.g., near a stone to be removed). In one embodiment, end effector618 is positioned such that retention member 620 may capture a stone.For example, end effector 618 may be positioned such that the stone isbetween the distal end of inner shaft 642 and the distal end of wallprotection member 624 (e.g., approximately within distance d). Device600 may then be brought into a configuration for capturing a stone. Toreach this configuration, retention member slider 604 may be actuated(e.g., moved distally) to advance stone retention member 620 out ofinner shaft 642 and into an expanded configuration for capturing thestone. In addition, wall protection member 624 may be deployed (e.g.,wall protection member 624 may be a balloon and may be expanded). Fromthe configuration for capturing the stone, stone retention member 620may be retracted to capture the stone. In some embodiments (e.g., whereeversion of wall protection member 624 is decoupled from movement ofstone retention member 620) a user may then actuate eversion slider 602to cause eversion of wall protection member 624. In some embodiments(e.g., where interference between a captured stone and inner shaft 642causes eversion), further retraction of stone retention member 620causes eversion of wall protection member 624. The eversion of wallprotection member 624 creates a pocket into which the stone may be drawnfor ease of removal. In some embodiments, wall protection member 624includes a balloon and eversion of wall protection member 624 causesdeflation of the balloon. With the stone stowed in wall protectionmember 624, end effector 618 may then be removed from the lumen of thepatient.

FIGS. 18A-18D illustrate an exemplary movement of shafts by articulatingsliders 602, 604. In FIG. 18A, end effector 618 is positioned near astone S to be captured. In FIG. 18B, a user actuates retention memberslider 604 (e.g., by moving retention member slider 604 distally, asillustrated by the large, solid-tipped arrow), which causes retentionmember 620 to advance distally out of inner shaft 642. Once advanced outof inner shaft 642, retention member 620 expands. Retention member 620may then capture stone S. For example, the user may retract retentionmember slider 604 to retract retention member 620 around stone 5,capturing stone S in retention member 620.

In FIG. 18C, wall protection member 624 has been expanded for receivingstone S and retention member 620. The user moves retention member slider604 proximally (large, solid-tipped arrow) to retract stone S towardswall protection member 624. In FIG. 18D, the user moves eversion slider602 proximally (large, solid-tipped arrow), causing wall protectionmember 624 to evert and form a pocket, into which retention member 620and stone S can be drawn (e.g., by further retraction of retentionmember slider 604). In some embodiments, wall protection member 624 mayat least partially evert prior to stone S being drawn into the pocket(e.g., prior to stone being partially covered by wall protection member624). With stone S captured and held in wall protection member 624, endeffector 618 may be withdrawn from the lumen of the patient.

Referring now to FIGS. 19A-19E, another alternative embodiment of astone removal device 700 is illustrated. This embodiment of device 700is similar to that described in reference to FIGS. 17 and 18A-18D, andthus includes a handle 712 with a retention member slider 704, an outershaft 716, an end effector 718, a retention member 720 with a retentionmember shaft 746, a wall protection member 724, an inner shaft 742, andoptionally any of the other features and/or components described abovefor any of the other embodiments. The primary difference between thisembodiment of device 700 and the previously described embodiment ofdevice 600 is that the current embodiment does not include an eversionslider. Instead, device 700 has an internal eversion mechanism 702,which is located within handle 712 and does not have an externalinterface for direct actuation by the user. This eversion mechanism 702is discussed further below.

FIGS. 19A-19E illustrate one embodiment of shaft movement as controlledby articulating retention member slider 704. In some embodiments, suchas the one illustrated in FIGS. 19A-19E, device 700 may have asimplified handle actuation configuration such that actuation ofretention member slider 704 alone may capture a stone S and evert wallprotection member 724. In this embodiment, the axial force of stoneretention member 720 containing a captured stone S on inner shaft 742creates eversion force that may cause inner shaft 642 to move relativeto outer shaft 616 causing wall protection member to evert. In thismanner, the embodiment may have only a single mechanism with which theuser interacts to capture the stone and evert wall protection member724.

To evert wall protection member 724, retention member 720 may overcomethe friction force in the proximal end created by a wall protectionmember seal or gasket. As a result, retention member shaft 746 may havea tendency to stretch rather than cause eversion if the axial stiffnessof retention member shaft 746 is too low. In this embodiment, innershaft 742 and retention member shaft 746 may be configured withsufficient stiffness to prevent substantial luminal stretching. Onesolution is to use a nitinol or stainless steel wire or hypotube for theretention member shaft 746. These shaft materials may have sufficientstiffness to induce eversion without stretching while also beingflexible enough for deployment in tortuous anatomy. A nitinol orstainless steel wire with a diameter of at least 0.005″ may havesufficient axial strength to prevent stretching, as does a stainlesssteel hypotube or braided shaft of at least 0.002″ of wall thickness.These configurations of wire or hypotubes may be sufficient for typicalworking lengths of about 0.8 m to about 1.6 m and other lengths.

In the embodiment illustrated in FIGS. 19A-19E, eversion slider 702 islocated within handle 712 and does not have an external interface fordirect actuation of the user. Actuation of retention member slider 704directly or indirectly causes physical interference with eversion slider702, causing eversion slider 702 to move without direct actuation byuser. In one embodiment, for example, the physical interference isdirectly between eversion slider 702 and retention member slider 704. Inanother embodiment, interference between a captured stone and innershaft 742 may cause movement of eversion slider 702. In someembodiments, there is a friction fit between eversion slider 702 andhandle 712 to resist movement of eversion slider 602 and thereby resisteversion/eversion of wall protection member 724. The physicalinterference may need to overcome this friction before wall protectionmember 724 is everted.

In FIG. 19A, end effector 618 of device 700 is positioned near a stone Sto be captured. FIG. 19B shows stone S captured in retention member 720.To capture stone 5, a user may, for example, actuate stone retentionmember slider 704 (e.g., by moving retention member slider 704 distally,as indicated by the arrow), which causes retention member 720 to advanceout of inner shaft 742. Then the retention member 720 may be used tocapture stone S. A portion of retention member slider 704 abuts eversionslider 702 within the handle 712, preventing further distal movement ofretention member slider 704. FIG. 19C shows wall protection member 724in an expanded (e.g., inflated) configuration. The user actuatesretention member slider 704 (e.g., by moving retention member slider 704proximally, as indicated by the arrow) to move the captured stone Stoward expanded wall protection member 724. In FIG. 19D, continuedactuation of retention member slider 704 (e.g., proximally, as indicatedby the dark arrow) causes movement of eversion slider 702 (e.g.,proximally, as indicated by the light arrow). For example, theretraction of captured stone S may cause physical interference betweenstone S and inner shaft 742 and/or wall protection member 724, therebycausing eversion of wall protection member 724. In another example,retention member shaft 746 may be coupled to inner shaft 742, such thatretraction of retention member shaft 746 with a captured stone causesretraction of inner shaft 742, thereby causing eversion of wallprotection member 724. In another example, the retraction of stone Scauses movement of eversion slider 702, which causes eversion of wallprotection member 724. The everted wall protection member 724 forms apocket into which stone S may be captured and held. With stone Scaptured and held in wall protection member 724, end effector 718 may bewithdrawn from the lumen of the patient.

FIG. 19E illustrates an example un-eversion step. In particular, FIG.19E shows un-eversion actuation (e.g., distal movement) of retentionmember slider 704 after stone S is captured in a partially everted wallprotection member 724. In an example, this articulation may causephysical interference of fittings within handle 712, thereby causingwall protection member 724 to un-evert. In another example, thisactuation may cause physical interference between retention memberslider 704 and eversion slider 702, thereby causing wall protectionmember 724 to start to un-evert. Continued un-eversion actuation maycause stone retention member 720 to be advanced out of wall protectionmember 724. Such an un-eversion step may be used, for example, to repeateversion for any reason. In another example, the un-eversion step may beperformed after the device is removed from the patient in order toretrieve stone S.

Referring now to FIGS. 20A-20F, yet another embodiment of a kidney stoneremoval device 800 (or “urinary tract stone removal device”) isillustrated. As with previously described embodiments, stone removaldevice 800 may be used to retrieve and remove whole kidney stones and/orstone fragments, as well as to dilate a portion of the ureter in someembodiments. Referring first to FIG. 20A, in this embodiment, stoneremoval device 800 generally includes a handle 812 at the proximal end,an outer shaft 816, and an several features at the distal end, which maybe referred to collectively as “end effectors” or “an end effector.” Inthis embodiment, the distal end includes a wire basket 820 (which is oneembodiment of a “retention member”), an expandable balloon 824 (which isone embodiment of a “wall protection member”), and an inner shaft 842,to which expandable balloon 824 is mounted. In this embodiment,expandable balloon 824 includes a rounded distal end 825, which will bediscussed in further detail in relation to FIG. 20F. Stone removaldevice 800 also may include a fluid inlet tube 810, although optionallytube 810 may be provided separately and may simply attach to device 800.

Handle 812 is located at the proximal end of outer shaft 816. In thisembodiment, handle 812 includes an inversion slider 802 for actuatingexpandable balloon 824 and a basket slider 804 for actuating wire basket820. (As in previous embodiments, the terms “eversion” and “inversion”may be used interchangeably and should not be interpreted as limiting.)In alternative embodiments, slider 802 and/or slider 804 may be replacedby a lever, a knob, a wheel, a button, or any other suitable mechanismby which a user may manipulate handle 812 to actuate movement ofexpandable balloon 824 and/or wire basket 820. In general, inversionslider 802 operates to evert expandable balloon 824, and basket slider804 operates to translate (advance and retract) wire basket 820. Wirebasket 820 may be connected to a basket shaft 850 (FIG. 20F), whichextends through inner shaft 842 and is connected proximally to basketslider 804. Stone removal device 800 may also optionally include any ofthe characteristics or features of the other embodiments of devices andsystems disclosed above.

Actuation of inversion slider 802 or basket slider 804 may causeactuation of one or more shafts of device 800. Inversion slider 802 maybe configured to cause at least partial eversion of expandable balloon824. Inversion slider 802 may be connected to inner shaft 842 (to whichexpandable balloon 824 may be attached), such that actuation ofinversion slider 802 causes movement of inner shaft 842 relative to oneor more of the other shafts. Basket slider 804 may be connected to wirebasket 820 via basket shaft 850, and actuation of basket slider 804 maycause movement of wire basket 820 and/or basket shaft 850 relative toone or more of the other shafts.

In some embodiments, the components of device 800 may be adapted suchthat the components are kept stationary by a friction fit, and themovement of the mechanisms actuates one or more components and overcomesthe friction fit. In some embodiments, the friction fit may be createdin the fit between a mechanism and handle 812. In some embodiments, thefriction fit may be created in a fit between a gasket (e.g., a rubbergasket) and a mechanism or a shaft. In some embodiments, inversionslider 802 is held stationary by friction through a seal used for a wallprotection member infusion port.

In some embodiments, the friction fit may be configured such that basketslider 804 and basket shaft 850 are stationary relative to inversionslider 802 and inner shaft 842, such that a user needs to control onlyone mechanism at a time. The friction may be such that the user's handcan provide enough force to overcome the friction and actuate basketslider 804, but other movements, such as the movement of inversionslider 802, would not result in wire basket 820 substantially movingrelative to inner shaft 842. In this manner, the user would not need tocontinuously prevent movement of basket slider 804 during actuation ofinversion slider 802. In some embodiments, the components of device 800may be held in position by a lock, and the movement of the mechanismsdisengages the lock and allows movement of one or more shafts.

In some embodiments, device 800 may be placed in an insertionconfiguration for inserting the distal end of outer shaft 816 into alumen of a patient and navigating to a target site. In thisconfiguration, inversion slider 802 may be in a distal-most position,and basket slider 804 may be in a proximal-most position. In thisconfiguration of sliders 802, 804, wire basket 820 may be positionedwithin inner shaft 842. In some embodiments, wire basket 820 may beself-expanding, and the confines of inner shaft 842 may prevent wirebasket 820 from expanding. The distal ends of outer shaft 816 and innershaft 842 may be spaced apart, such that expandable balloon 824 is in aninsertion configuration. For example, expandable balloon 824 may bedeflated to facilitate insertion.

Referring to FIG. 20B, a distal portion of handle 812 is shown with aproximal portion of outer shaft 816, with half of the outer shell ofhandle 812 removed to see the inner workings of handle 812. In thisembodiment, inversion slider 802 is keyed into a locking groove 814 onhandle 812 and is also coupled with a living hinge 846 on the oppositeside of handle 812. Living hinge 846 is a spring (plastic in thisembodiment, but could alternatively be made of other materials), thatprovides upward force to keep inversion slider 802 keyed into lockinggroove 814. When inversion slider 802 is keyed (or “locked”) intolocking groove 814, it cannot slide along handle 812. To disengage thelock, the user pushes down on inversion slider 802, thus compressingliving hinge 846 and disengaging inversion slider 802 from lockinggroove 814. This locking feature prevents accidental or unwanted slidingof inversion slider 802 during a procedure.

In some embodiments, one or more hypotubes may be attached to innershaft 842 and/or outer shaft 816 in the handle portion (for examplehypotubes that are about 1-3 inches long). This may facilitate a betterseal for balloon 824, since the hyptotube cannot be compressed (unlikecatheter shaft material), smoother travel as the shafts move in and outof the seals during actuation, increased durability due to bucklingresistance, and enhanced shaft alignment, since the hytotubes areresistant to bending.

In the illustrated embodiment, inversion slider 802 and basket slider804 are coupled with a frictional gasket or O-ring. When inversionslider 802 is moved proximally, basket slider 804 moves along with it.However, this coupling can be overridden by a user, simply by placing afinger on basket slider 804 to prevent it from moving when inversionslider 802 is moved. Unlike inversion slider 802, basket slider 804 actsindependently of inversion slider 802, to allow for stone capture simplywith wire basket 820. Inversion slider 802 is initially locked in placevia locking groove 814 and living hinge 846. This prevents accidentaleversion of expandable balloon 824 during deployment and allows stoneremoval device 800 to be used as a simple basket device, in other wordswithout deploying expandable balloon 824, if that is what the userdesires. Inversion slider 802 causes expandable balloon 824 to evert bypulling inner shaft 842 inward. In order to keep wire basket 820 closedduring the movement of inner shaft 842, a friction coupling is used tokeep wire basket 820 stationary within inner shaft 842.

FIGS. 20C-20E illustrate three steps of one exemplary method ofcapturing a stone with device 800. In each of FIGS. 20C-20E, the leftpanel shows a portion of handle 812, and the right panel shows what isoccurring at the distal end of device 800 as handle 812 is actuated.This illustrated portion of a stone retrieval method only involvescapturing the stone—it does not illustrate the steps of advancing stoneremoval device 800 to the stone location, inflating balloon 824, oradvancing wire basket 820 out of inner shaft 842, for example, althoughthose steps are described elsewhere in this disclosure.

As illustrated in FIG. 20C, initially inversion slider 802 and basketslider 804 are both in their most distal positions on handle 812. Inthese positions, as shown in the right panel, wire basket 820 is fullyadvanced out of the distal end of inner shaft 842 and is fully expandedfor stone capturing. In FIG. 20D, basket slider 804 slides proximallyalong handle (large arrow), and, as shown in the right panel, wirebasket 820 is partially drawn back into inner shaft 842 and thus ispartially collapsed to entrap a stone S. In this step, basket slider 804moves proximally independently of inversion slider 802, which has notmoved. (Inversion slider 802 is locked in place at this point, vialocking groove 814, as described above.) In FIG. 20E, inversion slider802 is now unlocked and sliding proximally along handle 812 (largedistal arrow). In this embodiment, inversion slider 802 is coupled withbasket slider 804 via a friction coupling, so that when the user movesinversion slider 802 proximally, basket slider 804 moves proximallyalong with it (large proximal arrow). As mentioned above, the reverse isnot true—in other words, basket slider 804 can be moved independently,without moving inversion slider 802, as illustrated in FIG. 20D. Theright panel in FIG. 20E shows only expandable balloon 824 and the stoneS, for enhanced clarity, so that that the stone S can be seen inside theeverted distal end of expandable balloon 824.

Referring now to FIG. 20F, a magnified view of the distal end of stoneremoval device 800 is illustrated. As seen here, a distal end of outershaft 816 extends partway into expandable balloon 824, and a proximalattachment leg 828 of balloon 820 is mounted onto a distal end of outershaft 816. Inner shaft 842 extends out of the distal end of outer shaft816, through the lumen of balloon 824, and out the distal end of balloon824. A distal attachment leg 830 of balloon 824 is mounted on a distalportion of inner shaft 842. Inner shaft 842 is moveable/translatableinto and out of (proximally and distally relative to) outer shaft 816,so that when inner shaft 842 is moved proximally into outer shaft 816(using inversion slider 802), it causes balloon 824 to evert. In thisembodiment, balloon 824 has a specific shape with a tapered proximalportion 826 and a rounded distal tip 825. We use the word taper to referto the narrowing of the balloon from its fully inflated maximum diameterto the balloon shaft diameter. This shape may be advantageous in that itwill help ensure preferential eversion of distal tip 825 when innershaft 842 is moved proximally. This preferential eversion is discussedabove in greater detail, but it has been found that the combination ofrounded distal tip 825 and a relatively long tapered proximal portion826 may be particularly effective in achieving this preferentialeversion. Rounded distal tip 825 also has an “edge free” inversionsurface, which may aid in smoother eversion. Another potential advantageof rounded distal tip 825 is that it may make it easier to manufactureballoon 824 using a balloon blowing process. For example, rounded distaltip 825 may facilitate insertion and removal of tooling during theblowing process. In other embodiment, balloon 824 may be manufacturedusing a dipping process, rather than a blowing process.

Balloon 824 may have any of a number of different sizes, according tovarious embodiments. In one exemplary embodiment, for example, themiddle, straight, tubular portion of balloon 824 (between rounded distaltip 825 and tapered proximal portion 826) has a length of approximately25 mm, and tapered proximal portion 826 has a length of approximately 10mm. In various embodiments, rounded distal tip 825 may have a length ofbetween about two times and about eight times less than the length oftapered proximal portion 826. The proximal attachment leg 828 may have alength of approximately 4 mm, the distal attachment leg 830 may have alength of approximately 3 mm, and balloon 824 may have an inflatedradius (from an outer surface on one side to an outer surface on anopposite side) of about 5 mm. In one embodiment, balloon 824 may beapproximately twice as thick near tapered proximal portion 826 than itis near rounded distal tip 825. This variation in thickness (in thisembodiment, half as thick at distal tip 825) may also help promotepreferential inversion of distal tip 825. These are only exemplarydimensions for one embodiment, however. Optionally, balloon 824 may bemade or, or coated with, a hydrophilic material to reduce friction alongthe ureteral wall.

As discussed elsewhere, the distal end of stone removal device 800 alsoincludes basket shaft 850, which is coupled directly with wire basket820. Basket shaft 850 moves in and out of the distal end of inner shaft842 via basket slider 804, to cause wire basket 820 to expand (when outof inner shaft 842) and collapse (when pulled back into inner shaft842). Pulling wire basket 820 partially back into inner shaft 842 causesit to collapse down over a stone to trap it.

Referring now to FIGS. 21A-21F, another embodiment of a stone removalmethod is illustrated, using stone removal device 800 and a ureteroscope860. For the purposes of this illustrative method, as well as for thisentire disclosure in general, ureteroscope 860 may be any standard,custom or as-yet-undeveloped ureteroscope or suitable endoscopic device.As illustrated in FIG. 20A, during a procedure, the distal end ofureteroscope 860 may be positioned near a target site, for example neara stone S to be removed. This step may be visualized, of course, viaureteroscope 860. In fact, any or all of the following steps may also bevisualized using ureteroscope 860, so the visualization part of thismethod will not be discussed further.

In a next step, as shown in FIG. 21B, stone removal device 800, hereseen only as outer shaft 816, may be advanced out of the distal end ofureteroscope 860, to a location that is next to the stone S or distal tothe stone S. In FIG. 21B, the distal end of outer shaft 816 ispositioned near a middle of one side of the stone S. Next, asillustrated in FIG. 21C, wire basket 820 may be advanced out of innershaft 842 (not visible in FIG. 21B) and outer shaft 816, so that itexpands around the stone S. (Basket shaft 850 is also not visible inFIG. 21C, because it is still located within outer shaft 816 and innershaft 824.). In another technique, wire basket 820 may be advanced outof inner shaft 842 in a location just distal to the stone S, and thenall of device 800 (sometimes including ureteroscope 860) may be pulledback proximally, until wire basket 820 surrounds the stone S. (In thisexample, as throughout this disclosure, “distal” and “proximal” are usedin terms of the device, not the patient on which it is being used—inother words, “distal” means toward or in the direction of the distal endof the device, relative to the proximal end of the device, and viceversa.)

As illustrated in FIG. 21D, wire basket 820 may next be partiallyretracted (or “pulled back” or “pulled proximally”) into inner shaft 842(e.g., by sliding basket slider 804 proximally to move basket shaft 850proximally within inner shaft 842), so that it partially collapsesaround the stone S, thus trapping or capturing the stone S securelywithin it. Referring to FIG. 21E, ureteroscope 860 may next be pulledback over stone removal device 800, to fully expose inflatable balloon824, which in turn may be inflated, for example using air. In someembodiments, inflatable balloon 824 may be inflated to a diameter ofabout 5 mm. In some embodiments, inflatable balloon 824 may be inflatedto a diameter that will expand a portion of a ureter, sometimes aconstricted ureter for example, which may help facilitate withdrawal ofthe stone S proximally through the ureter. In some embodiments, balloon824 may be inflated at an earlier stage in the method, such as beforewire basket 820 is extended out of inner shaft 842 and/or before wirebasket 820 is used to trap the stone S. Whenever the various steps areperformed at some point during the method, the stone S is securelytrapped in wire basket 820, and balloon 824 is inflated, as illustratedin FIG. 21E. There is often unexpected narrowing in the ureter.Currently, the only options are to push a uereteroscope through such anarrowing, usually while increasing irrigation, or remove the scope anduse a ureteral dilator under fluoroscopy. Kidney stone removal device800 and method allow for direct visualization of such narrow portions ofa ureter, using ureteroscope 860, as well as dilation of the narrowedportion, using balloon 824, to facilitate and/or expedite a successfulprocedure.

As shown in FIG. 21F, the next steps may involve pushing down oninversion slider 802 to unlock it, and sliding it proximally alonghandle 812. This proximal movement of inversion slider 802 causes twoactions at the distal end of stone removal device 800: (1) roundeddistal tip 825 of balloon 824 inverts; and (2) basket slider 804 movesproximally along handle 812 along with inversion slider 802 (they arefrictionally coupled), thus causing basket shaft 842, wire basket 820and the stone S to move proximally into rounded distal tip 825. FIG. 21Fdoes not show the stone S pulled all the way into balloon 824, buttypically during a removal procedure it will be pulled back until it iscovered on both sides by balloon 824. Use of a balloon inflation devicemay facilitate the use of two different pressures. In some embodiments,balloon 824 may be inflated to two different pressures during aprocedure: (1) a lower pressure (for example about 0.7-2 atm) forballoon inversion; and (2) a higher pressure (for example about 5-10atm) for balloon dilation of a narrowed portion of a ureter.

Next, ureteroscope 860 and stone removal device 800 can be pulled out ofthe ureter together, with the stone S trapped securely within balloon824, which helps prevent damage to the ureteral wall during stoneremoval. In some embodiments, the method may also involve dilating theureter with balloon 824 one or more times during withdrawal of stoneremoval device 800, to help facilitate device withdrawal and/or reducedamage to the wall of the ureter during withdrawal. Dilating duringremoval may be accomplished with the stone S located in balloon 824,prior to stone invagination, or by un-invaginating the stone S (pushinginversion slider 802 forward/distally to expose the stone S).

The above-described method may be used, for example, to remove wholekidney stones and/or kidney stone fragments of less than about 5 mm indiameter through a ureteroscope (flexible or semi-rigid). Stones ofgreater diameter may also be removed, using the above-described oralternative embodiments, although the dimensions of stone removal device800 may often lend themselves best to stones and/or fragments of about 5mm diameter or less. The method may also be used for gently dilating theureteral tract, as described above. This dilation functionality may beused to open up a narrow section of the ureter or provide temporaryexpansion if the removal force becomes higher than an acceptablethreshold for the user. Additionally, device 800 and method may be usedto prevent retropulsion of kidney stone fragments back into the kidneyduring a stone fragmentation procedure (e.g., lithotripsy). This may beaccomplished, for example, by inflating balloon 824 at a point distal tothe stone prior to fragmentation.

Referring now to FIGS. 22A and 22B, in some embodiments, balloon 824,including rounded distal tip 825, may have one or more longitudinalpleats 827 a, 827 b, which run along all or a portion of the length ofballoon 824, from the distal end to the proximal end. According to someembodiments, balloon 824 may have an inflated diameter of approximately5 mm (or more, in some embodiments), while also may have a deflated sizethat fits through a 3.5F (1.2mm) working channel of a ureteroscope. Whenstone removal device 800 is used, balloon 824 may often be deflated (byremoving the air from it) and pulled back into the ureteroscope channel.In some cases, balloon 824 may even be advanced again out of the channeland reinflated. Pleats 827 a, 827 b help facilitate the this process ofdeflating balloon 824 and retracting it back into the channel. Creatingpleats 827 a, 827 b (or “folds”) in balloon 824 during manufacturinggives balloon 824 a folding pattern, so it will collapse down duringdeflation (under vacuum) to a shape that will fit through theureteroscope again without bunching.

As illustrated in FIG. 22A, one embodiment may include three pleats 827a, and as shown in FIG. 22B, an alternative embodiment may include fivepleats 827 b. Other embodiments may include any other suitable number ofpleats. Pleats 827 a, 827 b will ideally provide a consistent,repeatable, folding pattern. They may be formed in balloon 824 duringmanufacturing, by running balloon 824 through a die, partiallyinflating, and then pulling vacuum again before sliding the balloonsheath on. It may also be done under moderate heat to further increasethe pleat memory of the balloon material. Pleats 827 a, 827 b may runthe entire length of balloon 824, and then may be straight or curvearound balloon 824, in alternative embodiments.

Although the above description is believed to be complete and accurate,it is directed toward a number of exemplary embodiments and is not meantto be exhaustive. Therefore, any of a number of different alterations,additions and subtractions may be made to any given embodiment, withoutdeparting from the scope of the invention, as it is defined by theclaims below. The description of the various embodiments is not intendedto limit the scope.

What is claimed is:
 1. A method for removing a urinary tract stone, themethod comprising: advancing a distal end of a ureteroscope into a bodylumen to a location near the urinary tract stone; advancing a distal endof a flexible stone removal device out of the distal end of theureteroscope; sliding a basket slider distally along a handle of thestone removal device to advance a wire basket out of an inner shaft ofthe stone removal device, thus allowing the wire basket to expand;sliding the basket slider proximally along the handle to trap theurinary tract stone within the wire basket; inflating an inflatableballoon on the stone removal device; sliding an inversion sliderproximally along the handle to invert a rounded distal tip of theinflatable balloon, wherein the inversion slider is frictionally coupledwith the basket slider, and wherein sliding the inversion sliderproximally automatically slides the basket slider proximally to pull thewire basket and the trapped urinary tract stone into the rounded distaltip of the inflatable balloon; and removing the ureteroscope and thestone removal device from the body lumen, along with the urinary tractstone, while the urinary tract stone is at least partially locatedinside the inflatable balloon.
 2. The method of claim 1, whereininflating the inflatable balloon comprises inflating to a first, lowerpressure, and wherein the method further comprises inflating theinflatable balloon to a second, higher pressure for dilating a narrowedportion of the body lumen, before trapping the urinary tract stone. 3.The method of claim 1, further comprising unlocking the inversion sliderbefore sliding it proximally along the handle.
 4. The method of claim 1,further comprising visualizing at least one of the steps of the method,using the ureteroscope.
 5. The method of claim 1, wherein advancing thedistal end of the stone removal device comprises advancing the distalend of the device distally beyond the urinary tract stone, the methodfurther comprising pulling the stone removal device proximally tosurround the urinary tract stone with the wire basket.
 6. The method ofclaim 1, wherein the urinary tract stone comprises a urinary tract stonefragment.
 7. The method of claim 1, wherein the urinary tract stonecomprises a urinary tract stone fragment, and wherein at least part ofthe method is performed during a lithotripsy procedure, to help preventmovement of the urinary tract stone fragment into a kidney.
 8. Themethod of claim 1, further comprising depressing the inversion sliderbefore sliding it, to unlock the inversion slider from an inversionslider lock in the handle.
 9. The method of claim 1, further comprisingholding a finger on the basket slider during movement of the inversionslider to override the automatic movement of the basket slider.
 10. Themethod of claim 1, wherein sliding the basket slider does notautomatically move the eversion slider when the eversion slider islocked in an inversion slider lock in the handle.
 11. The method ofclaim 1, wherein the inflatable balloon is inflated sufficiently todilate a narrow portion of the body lumen.
 12. The method of claim 1,further comprising inflating the balloon at least one time duringremoval of the stone removal device from the body lumen, to dilate anarrow portion of the body lumen.
 13. The method of claim 1, furthercomprising removing air from the inflatable balloon to reduce pressurein the inflatable balloon before inverting the rounded distal tip of theinflatable balloon.
 14. The method of claim 1, wherein the urinary tractstone is less than 5 mm in diameter.